100 assays (50 of each) per kit
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|Content:||100 assays (50 of each) per kit|
Short term stability: 2-8oC,
Long term stability: See individual component labels
|Stability:||> 2 years under recommended storage conditions|
|Analyte:||D-Lactic Acid, L-Lactic Acid|
|Linear Range:||0.5 to 30 µg of D- or L-lactic acid per assay|
|Limit of Detection:||0.21 mg/L|
|Reaction Time (min):||
~ 10 min (L-lactic acid),
~ 5 min (D-lactic acid)
|Application examples:||Wine, soft drinks, milk, dairy products, foods containing milk (e.g. dietetic foods, bakery products, baby food, chocolate, sweets and ice-cream), vinegar, fruit and vegetables, processed fruit and vegetables, meat products, food additives, paper (and cardboard), cosmetics, pharmaceuticals and other materials (e.g. biological cultures, samples, etc.).|
|Method recognition:||Methods based on this principle have been accepted by DIN, GOST, IDF, EEC, EN, ISO, OIV, IFU, AIJN and MEBAK|
The D-/L-Lactic Acid (D-/L-Lactate) (Rapid) test kit is used for the rapid and specific concurrent measurement and analysis of L-lactic acid (L-lactate) and D-lactic acid (D-lactate) in beverages, meat, dairy and food products.
Note for Content: The number of manual tests per kit can be doubled if all volumes are halved. This can be readily accommodated using the MegaQuantTM Wave Spectrophotometer (D-MQWAVE).
Explore more organic acid assay kit products.
- Extended cofactors stability. Dissolved cofactors stable for > 1 year at 4oC.
- Rapid total analysis time (concurrent / flexible D and L-lactic acid reaction format)
- D-lactate dehydrogenase reaction very rapid with most samples (~ 5 min)
- Very competitive price (cost per test)
- All reagents stable for > 2 years after preparation
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
Megazyme “advanced” wine test kits general characteristics and validation.
Charnock, S. J., McCleary, B. V., Daverede, C. & Gallant, P. (2006). Reveue des Oenologues, 120, 1-5.
Many of the enzymatic test kits are official methods of prestigious organisations such as the Association of Official Analytical Chemicals (AOAC) and the American Association of Cereal Chemists (AACC) in response to the interest from oenologists. Megazyme decided to use its long history of enzymatic bio-analysis to make a significant contribution to the wine industry, by the development of a range of advanced enzymatic test kits. This task has now been successfully completed through the strategic and comprehensive process of identifying limitations of existing enzymatic bio-analysis test kits where they occurred, and then using advanced techniques, such as molecular biology (photo 1), to rapidly overcome them. Novel test kits have also been developed for analytes of emerging interest to the oenologist, such as yeast available nitrogen (YAN; see pages 2-3 of issue 117 article), or where previously enzymes were simply either not available, or were too expensive to employ, such as for D-mannitol analysis.Hide Abstract
Grape and wine analysis: Oenologists to exploit advanced test kits.
Charnock, S. C. & McCleary, B. V. (2005). Revue des Enology, 117, 1-5.
It is without doubt that testing plays a pivotal role throughout the whole of the vinification process. To produce the best possible quality wine and to minimise process problems such as “stuck” fermentation or troublesome infections, it is now recognised that if possible testing should begin prior to harvesting of the grapes and continue through to bottling. Traditional methods of wine analysis are often expensive, time consuming, require either elaborate equipment or specialist expertise and frequently lack accuracy. However, enzymatic bio-analysis enables the accurate measurement of the vast majority of analytes of interest to the wine maker, using just one piece of apparatus, the spectrophotometer (see previous issue No. 116 for a detailed technical review). Grape juice and wine are amenable to enzymatic testing as being liquids they are homogenous, easy to manipulate, and can generally be analysed without any sample preparation.Hide Abstract
Efficient conversion of hemicellulose sugars from spent sulfite liquor into optically pure L-lactic acid by Enterococcus mundtii.
Hoheneder, R., Fitz, E., Bischof, R. H., Russmayer, H., Ferrero, P., Peacock, S. & Sauer, M. (2021). Bioresource Technology, 333, 125215.
Spent sulfite liquor (SSL), a waste stream from wood pulp production, has great potential as carbon source for future industrial fermentations. In the present study, SSL was separated into a hemicellulose derived sugar syrup (HDSS) and a lignosulfonic fraction by simulated moving bed chromatography. The recovery of SSL sugars in the HDSS was 89% and the fermentation inhibitors furfural, 5-hydroxymethylfurfural and acetic acid were removed by 98.7%, 60.5% and 75.5%, respectively. The obtained sugars have been converted to L-lactic acid, a building block for bioplastics, by fermentation with the lactic acid bacterium Enterococcus mundtii DSM 4838. Batch fermentations on HDSS produced up to 56.3 g/L L-lactic acid. Simultaneous conversion of pentose and hexose sugars during fed-batch fermentation of wildtype E. mundtii led to 87.9 g/L optically pure (>99%) L-lactic acid, with maximum productivities of 3.25 g/L.h and yields approaching 1.00 g/g during feeding phase from HDSS as carbon source.Hide Abstract
Predictive modeling of the early stages of semi-solid food ripening: Spatio-temporal dynamics in semi-solid casein matrices.
Kern, C., Stefan, T., Sacharow, J., Kügler, P. & Hinrichs, J. (2021). International Journal of Food Microbiology, 349, 109230.
A mechanistic, spatio-temporal model to predict early stage semi-solid food ripening, exemplary for semi-solid casein matrices, was created using software based on the finite element method (FEM). The model was refined and validated by experimental data obtained during 8 wk of ripening of a casein matrix that was inoculated by one single central injection of starter culture. The resulting spatio-temporal distributions of lactococci strains, lactose, lactic acid/lactate and pH allowed us to optimize a number of parameters of the predictive model. Using the optimized model, the agreement between simulation and experiment was found to be satisfactory, with the pH matching best. The predictive model unveiled that effective diffusion of substrate and metabolites were crucial for an eventual homogeneous distribution of the measured substances. Hence, while using the optimized parameters from the single injection model, an injection technology for starter culture to inoculate and ferment casein matrices homogeneously was developed by means of solving another optimization problem with respect to injection positions. The casein matrix inoculated by the proposed injection pattern (21 injections, distance = 19 mm) showed sufficient homogeneity (bacterial activity and pH distribution) after the early stages of ripening, demonstrating the potential of application of the injection technology for fermentation of casein-based foods e.g. cheese.Hide Abstract
Lactobacillus nasalidis sp. nov., isolated from the forestomach of a captive proboscis monkey (Nasalis larvatus).
Suzuki-Hashido, N., Tsuchida, S., Hayakawa, T., Sakamoto, M., Azumano, A., Seino, S., Matsuda, I., Ohkuma, M. & Ushida, K. (2021). International Journal of Systematic and Evolutionary Microbiology, 71(4), 004787.
Three strains (YZ01T, YZ02 and YZ03) of Gram-stain-positive, facultatively anaerobic rods were isolated from the forestomach contents collected from a captive male proboscis monkey (Nasalis larvatus) at Yokohama Zoo in Japan. Phylogenetic analysis of the 16S rRNA gene sequences revealed that these strains belonged to the genus Lactobacillus. Based on the sequence similarity of the 16S rRNA gene, Lactobacillus delbrueckii subsp. indicus JCM 15610T was the closest phylogenetic neighbour to YZ01T. Sequence analyses of two partial concatenated housekeeping genes, the RNA polymerase alpha subunit (rpoA) and phenylalanyl-tRNA synthase alpha subunit (pheS) also indicated that the novel strains belonged to the genus Lactobacillus. The average nucleotide identity and digital DNA-DNA hybridization (dDDH) between L. delbrueckii subsp. indicus and YZ01T were 85.9 and 31.4 %, respectively. The phylogenetic tree based on the whole genomic data of strains YZ01T, YZ02 and YZ03 suggested that these three strains formed a single monophyletic cluster in the genus Lactobacillus, indicating that it belonged to a new species. The DNA G+C content of strain YZ01T was 51.6 mol%. The major fatty acids were C16 : 0 and C18 : 1 ω9c. Therefore, based on phylogenetic, phenotypic and physiological evidence, strains YZ01T, YZ02 and YZ03 represent a novel species of the genus Lactobacillus, for which the name Lactobacillus nasalidis sp. nov. is proposed with the type strain YZ01T (=JCM 33769T=DSM 110539T).Hide Abstract
Lacticaseibacillus absianus sp. nov., isolated from the cecum of a mini-pig.
Bai, L., Paek, J., Shin, Y., Park, H. Y. & Chang, Y. H. (2021). International Journal of Systematic and Evolutionary Microbiology, 71(3), 004752.
A rod-shaped, facultative anaerobic, Gram-stain-positive bacteria, isolated from the cecum of a mini-pig, was designated as strain YH-lac23T. Analysis of 16S rRNA gene sequences revealed that the strain was closely related to Lacticaseibacillus daqingensis JCM 33273T (97.9 %), Lacticaseibacillus porcinae KCTC 21027T (96.2 %) and Lacticaseibacillus manihotivorans KCTC 21010T (95.7 %). Analysis of housekeeping gene sequences (pheS and recA) revealed that the strain formed a sub-cluster with L. daqingensis. The average nucleotide identity value for YH-lac23T and its most closely related strain (L. daqingensis) is 80.7 %. The main fatty acids are C18 : 1ω9c and C16 : 0. The cell wall contains the peptidoglycan of meso-diaminopimelic acid. The G+C content of the genomic DNA is 59.8 mol%. In view of the chemotaxonomic, phenotypic and phylogenetic properties, YH-lac23T (=KCTC 25006=JCM 33998) represents a novel taxon. The name Lacticaseibacillus absianus sp. nov. is proposed.Hide Abstract
Fortified blended foods prepared from fermented milk and cereal: Effect of storage conditions on composition, color, and pasting behavior.
Shevade, A. V., O’Callaghan, Y. C., O’Brien, N. M., O’Connor, T. P. & Guinee, T. P. (2021). Journal of Food Processing and Preservation, 45(5), e15419.
Fortified blended food powders (FBF) were prepared by blending fermented milk with parboiled wheat (FBFw), barley (FBFb), or oats (FBFo), incubating the blend, drying, milling, and fortifying the powder with vitamins, minerals, and refined soya oil. FBFs were stored at 15°C, 30°C, or 37°C for 0-18 months, and evaluated for compositional and functional properties. FBFo had lower contents of lactose and galactose, and higher contents of starch and fat, water-holding capacity (WHC) and pasting viscosity than FBFw or FBFb. Storage time and temperature affected composition (lactose, galactose, and lysine), color, WHC, pasting viscosity, and flow to a degree dependent on cereal type. FBFs stored at 15°C were generally stable over the 18 months, while those stored at 37°C underwent a rapid deterioration in color, WHC, and viscosity after storage times of ≤4 months. Storage of FBF at 15°C is recommended, whereas storage at 37°C should be avoided.Hide Abstract
Safety assessment of Lactobacillus reuteri IDCC 3701 based on phenotypic and genomic analysis.
Lee, B. S., Ban, O. H., Bang, W. Y., Chae, S. A., Oh, S., Park, C., Lee, M., Kim, S., Yang, J. & Jung, Y. H. (2021). Annals of Microbiology, 71(1), 1-6.
Purpose: Lactobacillus reuteri is one of the most largely studied human-commensal bacteria and widely used as a form of probiotics. Safety of probiotics has become increasingly important for human consumption due to increasing health-concerns in food industry. In this study, the safety of L. reuteri IDCC 3701 isolated from human breast milk was thoroughly investigated. Methods: Whole-genome sequence analysis was performed to identify antibiotic resistance and toxigenicity of L. reuteri IDCC 3701. Phenotypic analysis such as minimal inhibitory concentration, β-hemolysis, extracellular enzyme activity, and the production of biological amines and L/D-lactate, was investigated. Finally, acute oral toxicity test was performed to access L. reuteri IDCC 3701 safety. Results: Although multiple resistances to gentamicin and kanamycin were observed in L. reuteri IDCC 3701, it was revealed that these resistances are intrinsic and not transferable through whole-genome analysis. In addition, various phenotypic analysis concerning hemolysis, enzyme activity, and D-lactate production did not show any negative results. Although L. reuteri IDCC 3701 harbors a histidine decarboxylase gene, no biogenic amines were detected. Finally, L. reuteri IDCC 3701 exhibited no evidence of acute toxicity according to an in vivo study. Conclusion: Our findings demonstrate that L. reuteri IDCC 3701 is considered to be safe for human consumption as probiotics based on the in silico, in vitro and in vivo studies.Hide Abstract
Effect of Lactic Acid Fermentation on Quinoa Characteristics and Quality of Quinoa-Wheat Composite Bread.
Cizeikiene, D., Gaide, I. & Basinskiene, L. (2021). Foods, 10(1), 171.
The application of selected starter cultures with specific properties for fermentation may determine steady lactic acid bacteria (LAB) variety and the characteristics of fermented products that influence nutritional value, the composition of biologically active compounds and quality. The aim of this research was to evaluate the influence of different LAB on the biochemical characteristics of fermented quinoa. Moreover, total phenolic content (TPC), and the antimicrobial and antioxidant activities of protein fractions isolated from quinoa previously fermented with LAB were investigated. Quinoa additives, including quinoa fermented with Lactobacillus brevis, were incorporated in a wheat bread recipe to make nutritionally fortified quinoa-wheat composite bread. The results confirmed that L. plantarum, L. brevis, and L. acidophilus were well adapted in quinoa medium, confirming its suitability for fermentation. LAB strains influenced the acidity, L/D-lactic acid content, enzyme activity, TPC and antioxidant activity of fermented quinoa. The maximum phytase activity was determined in quinoa fermented with L. brevis. The results obtained from the ABTS radical scavenging assay of protein fractions confirmed the influence of LAB strain on the antioxidant activity of protein fractions. The addition of 5 and 10% of quinoa fermented with L. brevis did not affect the total titratable acidity of wheat bread, while 10% of fermented quinoa with L. brevis resulted in a higher specific volume. Fermented quinoa additives increased the overall acceptability of bread compared with unfermented seed additives.Hide Abstract
Improvement of lactic acid tolerance by cocktail δ-integration strategy and identification of the transcription factor PDR3 responsible for lactic acid tolerance in yeast Saccharomyces cerevisiae.
Yamada, R., Kumata, Y., Mitsui, R., Matsumoto, T. & Ogino, H. (2021). World Journal of Microbiology and Biotechnology, 37(2), 1-10.
Although, yeast Saccharomyces cerevisiae is expected to be used as a host for lactic acid production, improvement of yeast lactic acid tolerance is required for efficient non-neutralizing fermentation. In this study, we optimized the expression levels of various transcription factors to improve the lactic acid tolerance of yeast by a previously developed cocktail δ-integration strategy. By optimizing the expression levels of various transcription factors, the maximum D-lactic acid production and yield under non-neutralizing conditions were improved by 1.2. and 1.6 times, respectively. Furthermore, overexpression of PDR3, which is known as a transcription factor involved in multi-drug resistance, effectively improved lactic acid tolerance in yeast. In addition, we clarified for the first time that high expression of PDR3 contributes to the improvement of lactic acid tolerance. PDR3 is considered to be an excellent target gene for studies on yeast stress tolerance and further researches are desired in the future.Hide Abstract
Lentilactobacillus kribbianus sp. nov., isolated from the small intestine of a mini pig.
Bai, L., Paek, J., Shin, Y., Park, H. Y. & Chang, Y. H. (2020). International Journal of Systematic and Evolutionary Microbiology, 70(12), 6476-6481.
A Gram-stain-positive, facultative anaerobic, rod-shaped bacteria isolated from the small intestine of a mini pig was designated as strain YH-lac9T. 16S rRNA gene sequence analysis revealed that the strain belongs to the genus Lentilactobacillusand is closely related to Lentilactobacillus seniorisJCM 17472T, Lentilactobacillus rapiJCM 15042T and Lentilactobacillus diolivoransJCM 13927T, with 97.6, 96.2 and 95.7 % sequence similarity, respectively. Analysis of housekeeping gene sequences (pheS and recA) revealed that the strain formed a sub-cluster with L. senioris, supporting the results of 16S rRNA gene sequences analysis. The average nucleotide identity value for YH-lac9T and the most closely related strain is 74.1 %. The main fatty acids are C18 : 1ω9c, summed feature 7, C16 : 0 and summed feature 8. The G+C content of the genomic DNA is 37.8 mol%. In view of its chemotaxonomic, phenotypic and phylogenetic properties, YH-lac9T (=KCTC 25005=JCM 33997) represents a novel taxon. The name Lentilactobacillus kribbianus sp. nov. is proposed.Hide Abstract
Uncovering a superfamily of nickel-dependent hydroxyacid racemases and epimerases.
Desguin, B., Urdiain-Arraiza, J., Da Costa, M., Fellner, M., Hu, J., Hausinger, R. P., Desmet, T., Hols, P. & Soumillion, P. (2020). Scientific Reports, 10(1), 1-11.
Isomerization reactions are fundamental in biology. Lactate racemase, which isomerizes L- and D-lactate, is composed of the LarA protein and a nickel-containing cofactor, the nickel-pincer nucleotide (NPN). In this study, we show that LarA is part of a superfamily containing many different enzymes. We overexpressed and purified 13 lactate racemase homologs, incorporated the NPN cofactor, and assayed the isomerization of different substrates guided by gene context analysis. We discovered two malate racemases, one phenyllactate racemase, one α-hydroxyglutarate racemase, two D-gluconate 2-epimerases, and one short-chain aliphatic α-hydroxyacid racemase among the tested enzymes. We solved the structure of a malate racemase apoprotein and used it, along with the previously described structures of lactate racemase holoprotein and D-gluconate epimerase apoprotein, to identify key residues involved in substrate binding. This study demonstrates that the NPN cofactor is used by a diverse superfamily of α-hydroxyacid racemases and epimerases, widely expanding the scope of NPN-dependent enzymes.Hide Abstract
Thermophilic lactic acid bacteria affect the characteristics of sourdough and whole-grain wheat bread.
Cizeikiene, D., Jagelaviciute, J., Stankevicius, M. & Maruska, A. (2020). Food Bioscience, 38, 100791.
Application of selected starter cultures for sourdough propagation may ensure stable lactic acid bacteria (LAB) diversity and defined properties of sourdough that affect quality. The impact of Lactobacillus delbrueckii ssp. Bulgaricus MI, L. rossiae GL14 and L. acidophilus DSM 20079 as starter cultures were investigated for spoilage prevention and whole-grain wheat and sourdough bread properties. Whole-grain wheat sourdough propagated with these strains showed high phytase, amylase and xylanases activities. The highest phytase activity was obtained in sourdough prepared with L. bulgaricus MI. The results of gas chromatography–mass spectrometry using solid-phase microextraction showed that the compositions of volatile compounds in sourdough and whole-grain wheat bread depended on the LAB starter. In bread with L. acidophilus, 3-octen-2-ol and n-hexadecane were found, whereas those compounds were not found in other bread samples or in sourdough. Tetrahydrofurfuryl acetate was found only in bread prepared with L. bulgaricus MI sourdough. N-Pentadecane was found only in bread prepared with L. rossiae sourdough and bread prepared with spontaneous sourdough. The application of thermophilic sourdough increased bread porosity, elasticity, crumbliness and moisture content, but did not influence crumb hardness. Moreover, the fungal spoilage on the bread crust surface was suppressed using sourdough prepared with thermophilic LAB. The strain of LAB used for sourdough preparation influenced the shelf-life of bread.Hide Abstract
Improvement of Polymer Grade L-Lactic Acid Production Using Lactobacillus rhamnosus SCJ9 from Low-Grade Cassava Chips by Simultaneous Saccharification and Fermentation.
Unban, K., Puangkhankham, N., Kanpiengjai, A., Govindarajan, R. K., Kalaimurugan, D. & Khanongnuch, C. (2020). Processes, 8(9), 1143.
The present study aims to examine the process for L-lactic acid production from low-grade cassava chips (LGC) using a two-step fermentation approach (TSF) and simultaneous saccharification and fermentation (SSF) by proficient, newly isolated Lactobacillus rhamnosus strain SCJ9. The optimized medium composition revealed by response surface methodology for TSF was 166 g/L LGC hydrolysate and 20 g/L yeast extract (YE), while other medium components were fixed (g/L) as follows: tween80 (2.0), (NH4)2HPO4 (2.0), CH3COONa∙3H2O (6.0), (NH4)2HC6H5O7 (2.0), MgSO4∙7H2O (0.5), and MnSO4∙H2O (0.3). Based on the optimization conditions, the maximum experimental L-lactic acid of 134.6 g/L was achieved at 60 h fermentation time with a production efficiency of 89.73%, 0.95 g/g yield and 2.24 g/L/h productivity. In contrast, L-lactic acid production by SSF under optimized concentrations of thermostable-α-amylase (AA) and glucoamylase (GA) gave maximum L-lactic acid of 125.79 g/L at only 36 h fermentation time which calculated to the production efficiency, yield and productivity of 83.86%, 0.93 g/g and 3.49 g/L/h, respectively. The L-lactic acid production obtained from SSF was significantly improved when compared to TSF based on lower enzyme loading usage, shorter hydrolysis time and increase in production efficiency and productivity. Furthermore, there were no significant differences in the production by SSF between experiments conducted in laboratory bottle and 10-L fermenter. The results indicated the success of up-scaling for L-lactic acid production by SSF which could be developed for a further pilot-scale production of L-lactic acid.Hide Abstract
Construction of lactic acid-tolerant Saccharomyces cerevisiae by using CRISPR-Cas-mediated genome evolution for efficient D-lactic acid production.
Mitsui, R., Yamada, R., Matsumoto, T., Yoshihara, S., Tokumoto, H. & Ogino, H. (2020). Applied Microbiology and Biotechnology, 104(21), 9147-9158.
Lactic acid (LA) is chemically synthesized or fermentatively produced using glucose as substrate, mainly using lactic acid bacteria. Polylactic acid is used as a biodegradable bioplastic for packaging materials, medical materials, and filaments for 3D printers. In this study, we aimed to construct a LA-tolerant yeast to reduce the neutralization cost in LA production. The pHLA2-51 strain was obtained through a previously developed genome evolution strategy, and transcriptome analysis revealed the gene expression profile of the mutant yeast. Furthermore, the expression of the genes associated with glycolysis and the LA synthesis pathway in the LA-tolerant yeast was comprehensively and randomly modified to construct a D-LA-producing, LA-tolerant yeast. In detail, DNA fragments expressing thirteen genes, HXT7, HXK2, PGI1, PFK1, PFK2, FBA1, TPI1, TDH3, PGK1, GPM1, ENO2, and PYK2, and D-lactate dehydrogenase (D-LDH) from Leuconostoc mesenteroides were randomly integrated into the genomic DNA in the LA-tolerant yeast. The resultant engineered yeast produced about 33.9 g/L of D-LA from 100 g/L glucose without neutralizing agents in a non-neutralized condition and 52.2 g/L of D-LA from 100 g/L glucose with 20 g/L CaCO3 in a semi-neutralized condition. Our research provides valuable insights into non-neutralized fermentative production of LA.Hide Abstract
Production of a yeast-free focaccia with reduced salt content using a selected Leuconostoc citreum strain and seawater.
De Bellis, P., Montemurro, M., D'Imperio, M., Rizzello, C. G., Sisto, A. & Lavermicocca, P. (2020). LWT, 134, 109918.
A biotechnological protocol to produce a focaccia (a typical Italian flat bread) without bakers' yeast addition and with reduced salt was developed, to meet the current needs of the consumer. Based on its leavening capability, the Leuconostoc citreum strain C2.27 was selected to be used as a starter instead of the baker's yeast and inoculated in a liquid sourdough (type-II) for the production of the “yeast-free” focaccia. The addition of different NaCl concentrations and the replacement of the salt with food grade seawater were evaluated, and the capability of the selected strain to affect technological, nutritional and sensory features of the focaccia investigated. A significant improvement of the nutritional characteristics of the focaccia was observed compared to the control (leavened with bakers' yeast and added with NaCl 1.5 g/100 g) using 0.7 g/100 g of salt in the form of NaCl or seawater. Besides the reduced Na content (66% lower than the control), focaccia with seawater also showed a higher content of Ca2+ and Mg2+ (ca. 36% and 53%, respectively), and the lowest predicted glycemic index compared to the other experimental focaccia.Hide Abstract
Influence of the Microalga Chlorella vulgaris on the Growth and Metabolic Activity of Lactobacillus spp. Bacteria.
Ścieszka, S. & Klewicka, E. (2020). Foods, 9(7), 959.
The aim of this study was to evaluate the effect of the algae Chlorella vulgaris on the growth, acidifying activity, proportion of lactic acid isomers, and enzymatic profile of Lactobacillus brevis (ŁOCK 0944, ŁOCK 0980, ŁOCK 0992, and MG451814) isolated from vegetable silages. The results indicated that adding algae at concentrations of 0.1% (w/v) and 1.5% (w/v) to the Lactobacillus spp. growth medium accelerated the growth of bacteria and thus shortened their phase of logarithmic growth. The acidifying activity of the tested Lactobacillus brevis increased with an increased concentration of algae. Lactobacillus spp. cultured in the presence of Chlorella vulgaris showed higher production of L-lactic acid and lower D-lactic acid production. Moreover, the addition of algae changed the enzymatic activity of lactic acid bacteria; for instance, Lactobacillus brevis ŁOCK 0980 demonstrated more enzymatic activity of valine arylamidase, α-galactosidase, and α-glucosidase. Combining Lactobacillus brevis with the algae Chlorella vulgaris allows for the creation of innovative, functional products which confer favorable properties to the final product and open new horizons for the food industry.Hide Abstract
Portuguese cacholeira blood sausage: A first taste of its microbiota and volatile organic compounds.
Belleggia, L., Ferrocino, I., Reale, A., Boscaino, F., Di Renzo, T., Corvaglia, M. R., Cocolin, L., Milanović, V., Cardinali, F., Garofalo, C., Clementi, F., Aquilanti, L. & Osimani, A. (2020). Food Research International, 136, 109567.
Among typical Portuguese sausages, the cacholeira blood sausage undoubtedly represents one of the most popular preparations. To the authors’ knowledge, a lack of information on both the microbiota and the volatile organic compounds (VOCs) of this blood-containing sausage emerges from the available scientific literature. This study represents the first characterization of physico-chemical, microbiological and volatile traits of Portuguese cacholeira blood sausage. To this end, ready-to-eat cacholeira blood sausages were collected from two production batches manufactured in summer (batch 1) and autumn (batch 2). Viable counts showed active microbial communities mainly composed by lactic acid bacteria, coagulase negative cocci, enterococci and eumycetes. The metataxonomic approach showed a simple bacterial composition, which was dominated by Lactobacillus sakei in both the analyzed batches (1 and 2) considered. Carnobacterium, Enterococcus, Kluyvera, Lactococcus and Serratia were found as minor genera. The mycobiota varied according to the production season. Batch 1 was dominated by Starmerella apicola, Debaryomyces hansenii and Candida tropicalis, whereas batch 2 was dominated by D. hansenii. Moreover, Aspergillus spp., Kurtzmaniella zeylanoides, Saccharomyces cerevisiae, Kurtzmaniella santamariae, Brettanomyces bruxellensis and Pichia kluyveri were detected in both the batches as minority species. Seventy-two volatile compounds were identified, including esters, phenols, terpenoids, acids, alcohols, ketones, aldehydes, lactones, furans, sulphur and nitrogen compounds. Significant differences were seen in the amount of some compounds, as a feasible consequence of differences in the raw materials, artisan production and seasonality.Hide Abstract
Anticandidal activity of Lactobacillus spp. in the presence of galactosyl polyols.
Lipinska-Zubrycka, L., Klewicki, R., Sojka, M., Bonikowski, R., Milczarek, A. & Klewicka, E. (2020). Microbiological Research, 240, 126540.
Yeasts have a substantial impact on the contamination and loss of food. In this study, we applied bacteria of the genus Lactobacillus as natural biopreservatives. Anticandidal strains of bacteria were selected from among 60 strains of bacteria grown which were each with nine polyols or galactosyl polyols. Polyols and galactosyl polyols can act as prebiotics for lactic acid bacteria and can enhance the antifungal properties of bacteria by affecting their metabolism. The galactosyl polyols significantly improved the anticandidal activity of most of the bacteria we tested. Based on the screening, the most promising strains of bacteria were selected, and their metabolites (both primary and secondary) and enzymatic activity were characterized in the presence of polyols and galactosyl polyols. The qualitative and quantitative content of bacterial metabolites depended both on the bacterial strain and the type of culture medium. A wide variety of antifungals produced by bacteria, such as fatty acids, hydroxy fatty acids, and other acidic products with potential antagonistic activity (phenyllactic acid or hydroxyphenyllactic acid) were detected. The bacteria produced a high concentration of phenyllactic acid in the presence of galactosyl polyols (up to 84.3 mg/L). This finding could suggest that this metabolite may have a significant impact on the antifungal properties of lactobacilli against yeast. Galactosyl polyols influenced the enzymes involved in the synthesis of fatty acids and hydroxylated fatty acids (esterase lipase, acid phosphatase, and α-glucosidase). The mechanism of the antifungal effect of lactobacilli may be based on the synergistic effect of their primary and secondary metabolites, in particular phenyllactic acid.Hide Abstract