Diversity Of Lactic Acid Bacteria Research Articles

Polyphasic Characterisation of Non-Starter Lactic Acid Bacteria from Algerian Raw Camel’s Milk and Their Technological Aptitudes

SUMMARYResearch backgroundConsumption of spontaneously fermented camel´s milk is common in Algeria, making it a feasible source of diverse lactic acid bacteria (LAB) with the potential to be used as adjunct cultures to improve quality and safety of fermented dairy products.Experimental approachTwelve raw camel´s milk samples were used as a source of indigenous LAB, which were further characterised by examining39 phenotypic traits with technological relevance.Results and conclusionsThirty-five non-starter LAB (NSLAB) were isolated from 12 Algerian raw camel's milk samples and they were microbiologically, biochemically and genetically characterised. Some isolates showed proteolytic activity, acidifying capacity, the ability to use citrate, and to produce dextran and acetoin. Ethanol, acetaldehyde, methyl acetate, acetoin and acetic acid were the major volatile compounds detected. Cluster analysis performed using the unweighted group with arithmetic average (UPGMA) method, and based on the thirty-nine phenotypic characteristics investigated, reflected the microbial diversity that can be found in raw camel´s milk.Novelty and scientific contributionThe isolated strains, from a non-typical source, showed interesting technological traits to be considered as potential adjunct cultures. Cluster analysis based on the examined phenotypic characteristics proved to be a useful tool for the typification of isolates when no genetic information is available. These findings may be of use towards an industrialised production of camel's milk dairy products.

Data on the diversity of lactic acid bacteria isolated from raw and fermented camel milk.

Lactic acid bacteria (LAB) are the dominant and advantageous microorganisms of raw and fermented camel milk; these bacteria have the potential to develop functional camel-milk-derived products and can be used in dairy technology. This article presents data on the diversity of LAB, isolated from raw and fermented camel milk. In total, from two samples of raw camel milk and one sample of fermented camel milk, seventeen isolates of LAB were isolated. The data of genetic identification of strains, which was performed through analysis of the 16S rRNA gene sequence, is presented. According to this data, the prevailing number of LAB belong to the Lactobacillus genus – 53%. Following species of Lactobacillus bacteria were determined – fermentum, casei, curizae, oryzae, brevis, plantarum, rhamnosus, paracasei. The next prevailing number of lactic acid bacteria belong to the Pediococcus genus – 23%, represented by acidilactici and pentosaceus species. Lactic acid bacteria of Weissella and Enterococcus genera comprised 12% each from total abundance. These results can be used for a further selection of potential starter cultures for functional camel-milk-derived products.

Diversity of lactic acid bacteria in Moutai-flavor liquor fermentation process

ABSTRACT Maotai-flavor liquor, derived from a multi-stage solid fermentation process, is one of the most popular liquors in China. Its quality and flavor are closely related to diverse lactic acid bacteria (LAB). It is therefore significant to characterize LAB for the manufacturing of Maotai-flavor liquor. In this study, LAB in solid state fermentation stages were analyzed through high-throughput sequencing and cultivation-dependent methods during the fermentation process. In total, 65 LAB species were identified in the fermented matrix, showing a much higher LAB diversity than other types of Chinese liquor. In addition, discrepancies were found to exist in the dominant LAB community structures during different fermentation stages, and strains of the Lactobacillus genus were found to be the most dominant LAB. Furthermore, 33 LAB species were identified from the fermentation matrix through the cultivation and 16 S rRNA analysis of single isolates, thus representing 50.8% coverage of the detected LAB species. The relative abundance of isolated LAB in the total abundance of LAB was 95.9% during the fermentation process. In doing so, Lac2 and Lac13, two potentially new LAB species, were isolated. To the best of our knowledge, this study represents the identification of the highest number of LAB species by cultivation-dependent methods from fermented grains of Chinese liquor. In summary, this study monitored the LAB species composition of solid fermented matrix during the fermentation of Maotai-flavor liquor and has highlighted the potential importance of the higher abundance of LAB and the effect it has on the unique flavor of Maotai liquor.

Genetic diversity of lactic acid bacteria isolated from Sumbawa horse milk, Indonesia

Abstract. Kusdianawati, Mustopa AZ, Fatimah, Budiarto BR. 2020. Genetic diversity of lactic acid bacteria isolated from Sumbawa horse milk, Indonesia. Biodiversitas 21: 3225-3233. LAB from Sumbawa horse milk has good potential antimicrobial and probiotic agents. It is known, the study on LAB diversity based on its phenotypic characters is difficult to be distinguished. However, the development of molecular characterization based on the genotypic characteristic could be done for LAB diversity analysis. The aim of this study is to obtain the genetic diversity of LAB from Sumbawa horse milk collected from Penyaring Village and Lennanguar Village, Sumbawa, West Nusa Tenggara Indonesia. LAB strains were identified based on their genotypic characteristics, including their randomly amplified polymorphic DNA (RAPD) primers profiles and 16S ribosomal RNA (rRNA) sequences. The result of RAPD-PCR analysis showed 5 clusters of dendrograms resulted from GTG5 and LB2 primer amplification. Based on 16 rRNA sequences result, the phylogenetic tree was constructed and revealed 7 species of LAB i.e: SK 1.5, SKP K.3, SKP K.5, SKP K.9/SKP K.7/M.SKP K.3, SKL K.4, M.SKL K.1/ M.SKL K.5, and SKP K.4 belonging to the species of Enterococcus faecium, Weissella confusa, Lactococcus garvieae, Enterococcus thailandicus, Lactobacillus fermentum, Enterococcus faecalis, and Lactococcus petauri. In this study, the bacteria from Enterococcus sp., Lactococcus garvieae, and Lactococcus petauri existed as a novel of bacteria which means they have not been isolated and identified in Sumbawa horse milk compared to the previous findings.

Antiviral Mechanisms Related to Lactic Acid Bacteria and Fermented Food Products

The Covid-19 pandemics laid stress on the significance of having a strong immune system in coping with viral infections. Nutrition is important in the modulation of our immune systems. Recent studies have shown that probiotics, most of which are lactic acid bacteria (LAB) naturally present in fermented food products, can boost the immune system of their host. Although responses are generally strain and dose dependent, in one way or another, most LAB are capable of enhancing both the innate and the adaptive immune responses in animal model systems. In addition to their ability of boosting the immune system, LAB directly or indirectly by means of the fermentation process, can generate bioactive metabolites having antiviral properties, such as peptides. LAB are shown to have antiviral mechanisms that affect both upper respiratory tract and gastrointestinal viral infections. Not only live cells but also heat-killed cells of probiotics (paraprobiotics) are shown to be effective. These wide range of antiviral mechanisms suggest that the diversity of LAB in the food product is likely to enhance the variety and strength of health benefits obtained from fermented foods. Traditional fermented foods have significantly higher microbiodiversity with respect to the LAB species, as compared to those produced by commercial cultures. This is particularly valid for the Lactobacilli, where several species and strains have proven to be antiviral probiotics and are natural inhabitants of fermented foods at the same time. While drawing attention to the antiviral properties of both live and dead cells of LAB, this review aims to underline the significance of supporting our health with the wealth of foods that are rich in terms of their microbial diversity. Further scientific research must focus on the several technical, biological, and clinical aspects of traditional fermentations.

Characterization of Indigenous Lactic Acid Bacteria in Cow Milk of the Maltese Islands: A Geographical and Seasonal Assessment.

A geographical and seasonal assessment of indigenous lactic acid bacteria (LAB) in Maltese cow milk was conducted in this study. To investigate this, milk was collected from different regions of Malta during winter and summer seasons. Total viable counts (TVC) and LAB population were enumerated. Afterwards, LAB were isolated and identified by molecular methods. According to the results, similar TVC were enumerated on winter and summer samples, while highest LAB population was detected on summer samples. LAB isolates were grouped in seven different clusters which were assigned to Lactobacillus casei, Pediococcus pentosaceus, Lactobacillus plantarum, Weissella paramesenteroides, Lactobacillus rhamnosus, Lactococcus lactis, and Lactococcus garvieae. In addition, Enterococcus and Streptococcus species were also isolated. Season seemed to affect the genus/species of LAB since Lactobacillus were mainly isolated from winter samples, while Lactococcus and Enterococcus species were the main genera identified in summer samples. Regarding the geographical distribution, the majority of the Lactobacillus spp. were isolated from the South-eastern region in both seasons. In conclusion, through this study the diversity of indigenous LAB in the Maltese cow milk was monitored for the first time and highlighted that the microbial communities are affected by seasonality and geographical distribution of the farms.

Molecular identification and phylogenetic analysis of lactic acid bacteria isolated from goat raw milk

The aim of this study was to identify the genetic diversity of lactic acid bacteria (LAB) isolated from the local goat's milk. A total of 100 raw milk samples were collected from the different Basrah local markets. All the samples were cultured in the De man, Rogosa, and Sharpe (MRS) medium which enhances the growth of lactic acid bacteria. The result of the study showed that the only 64 lactic acid bacteria isolated gave the Gram-positive and catalase-negative were 64 (64%). All the suspected isolates were detected and identified by using polymerase chain reaction (PCR) targeting the 16S rRNA gene and DNA sequencing. The sequencing results showed that 9 strains belong to Lactococcus spp. and 6 strainsbelongto Lactobacillus spp. and all tested isolates had similarity over 99% with those recorded in the GenBank of The National Centre for Biotechnology.

Dynamics and species diversity of lactic acid bacteria involved in the spontaneous fermentation of various palm tree saps during palm wine tapping in Côte d'Ivoire.

To document and speed up research on the usefulness and selection of potential health-promoting bacterial starter cultures from unexplored fermented saps of various palm species in Côte d'Ivoire, benchmark tapping processes were successfully developed and implemented at field level. Therefore, spontaneously fermented saps of three palm species (Elaeis guineensis, Raphia hookeri, Borassus aethiopum) were collected throughout tapping process and lactic acid bacteria (LAB) diversity and dynamics were studied through a multiphasic approach. Overall microbiological analysis revealed a LAB species diversity throughout tapping process. LAB isolates belonged to two main (GTG)5-PCR clusters, namely Fructobacillus durionis (40.33%) and Leuconostoc mesenteroides (45.66%), with Leuconostoc pseudomesenteroides, Lactobacillus paracasei, Lactobacillus fermentum Weissella cibaria, Enterococcus casseliflavus and Lactococcus lactis occurring occasionally. LAB diversity was higher in fermented saps from E. guineensis (8 species) than those of R. hookeri (5 species) and B. aethiopum (3 species). Dynamic study revealed that F. durionis and L. mesenteroides dominated the fermentations from the beginning until the end of tapping process in all palm wine types. But the earlier stages of the process were also populated by some species like W. cibaria, L. pseudomesenteroides and L. fermentum, which population decreased or disappeared after some days. Also, species of Enterococcus and Lactococcus genera were sporadically detected uniquely in sap from E. guineensis. This study is the first to investigate extensively the LAB diversity and dynamics throughout palm trees tapping process in Côte d'Ivoire and is relevant for future selection of health promoting bacteria.

Phenotypic and genotypic characterization of Lactobacilli and Pediococci isolated from traditional Algerian fermentation products

In Algeria, as in many other countries of the world, there are several tradi-tional dairy products whose method of production has been driven from the cultural heritage of the population. These products are derived from the processing of milk in order to extend their shelf life. In the present study, a batch of 40 samples of fermented dairy products, collected from different regions in Algeria was subjected to a microbiological analysis, in order to determine the diversity of lactic acid bacteria (Lactobacilli and Pediococci) and to study their technological characteristics. Among 463 lactic acid bacte-ria isolated, 168 strains were selected. A phenotypic identification, based on morphological and biochemical criteria has been performed followed by a genotypic characterization by PCR and sequencing of the gene coding for 16S rRNA, using advanced molecular techniques and large-scale bioinformatics software. The results obtained showed that the lactic acid bacteria isolated from the fermented dairy products belonged to the genera Pediococcus and Lactobacillus with a dominance of the genus Lactobacillus compared to the total number of identified strains. This confirm that Lactobacilli do have sta-ble growth in acidic environment.

Profiling of koumiss microbiota and organic acids and their effects on koumiss taste

BackgroundKoumiss is a naturally fermented mare’s milk. Over recent decades, numerous studies have revealed the diversity of lactic acid bacteria in koumiss. However, there is limited information available regarding its secondary major component yeast profile.ResultsA total of 119 bacterial and 36 yeast species were identified among the 14 koumiss samples. The dominant bacterial species in koumiss were Lactobacillus helveticus, Lactobacillus kefiranofaciens, Lactococcus lactis, Lactococcus raffinolactis, and Citrobacter freundii. The main yeast species were Dekkera anomala, Kazachstania unispora, Meyerozyma caribbica, Pichia sp.BZ159, Kluyveromyces marxianus, and uncultured Guehomyces. The bacterial and yeast Shannon diversity of the Xilinhaote-urban group were higher than those of the Xilingol-rural group. The most dominant organic acids were lactic, acetic, tartaric, and malic acids. Lactic acid bacteria species were mostly responsible for the accumulation of those organic acids, although Kazachstania unispora, Dekkera anomala, and Meyerozyma caribbica may also have contributed. Redundancy analysis suggested that both bacteria and yeast respond to koumiss flavor, such as Lactobacillus helveticus and Dekkera anomala are associated with sourness, astringency, bitterness, and aftertaste, whereas Lactococcus lactis and Kazachstania unispora are associated with umami.ConclusionsOur results suggest that differences were observed in koumiss microbiota of Xilinhaote-urban and Xilingol-rural samples. The biodiversity of the former was higher than the latter group. Positive or negative correlations between bacteria and yeast species and taste also were found.

Isolation and identification of lactic acid bacteria in hive of Apis dorsata from semi-arid tropical climate in Benu village, East Nusa Tenggara

Lactic Acid Bacteria (LAB) have been isolated from the hive of Giant Honey Bee (Apis dorsata) origin from tropical climate. Information about the diversity of LAB from the hive of A. dorsata from Benu Village has not been found yet. The information is important as a preliminary study of the potential of biological resources for food functional development in the future. Therefore, it is needed to research on diversity of LAB that isolated from the hive of A. dorsata from the village of Benu as an area of semi-arid tropical climate. The purpose of this study is determine the diversity of LAB isolated from the hive of A. dorsata from Benu Village. This research is important because it provides preliminary information about the diversity of LAB species from the hive of A. dorsata from Benu Village as a representation of semi-arid tropical climate. Profile of Denaturing Gradient Gel Electrophoresis showed the presence of seven LAB isolates from the hive of A. dorsata in Benu Village. This is an early indication that hive of A. dorsata from semi-arid tropic climate has the potential as a biological resources of LAB that important for food funtional development in the future.

Identification of lactic acid bacteria and acetic acid bacteria of lampung cocoa beans fermentation

The quality of chocolate influenced by cocoa varieties, growth conditions, and fermentation. As a part of post-harvesting treatments, cocoa beans fermentation affects biochemical transformations resulting in the aroma, color, and taste of chocolate. Lactic acid bacteria (LAB) and acetic acid bacteria (AAB) along with yeasts are involved during during cocoa beans fermentation. In this study, the diversity of LAB and AAB of cocoa beans fermentation from Lampung will be identified. Fortykgs of cocoa beans undergo spontaneous box fermentation for five days, with 24 hours intervals of sampling. DeManRogosa Sharpe (MRS) Agar and Glucose Yeast Peptone (GYP) Agarwere used for LAB and AAB enumeration, respectively. Morphology of each colony were identified and molecular identification by analyzing 16S rRNA gene. As results, the growth of LAB reach its highest level on the zero and fifth day of fermentation to 106 CFU/mL and the growth of AAB reach 106 CFU/mL as well.Lactobacillus plantarum, L. fermentum and L. pentosusare the main species of lactic acid bacteria, and Acetobacterpasteurianusand A. tropicalisas the main species of acetic acid bacteria. These results describe more about the diversity of Indonesian cocoa that could be applied for starter culture development.

Identifying the Diversity of Dominant LABs from Fermented Dairy Products Dahi and Yoghurt in Eastern Region of Nepal

The aim of this study was to isolate and identify lactic acid bacteria diversity from dahi/ yoghurt. Curd, also known as commercially prepared yoghurt or homemade Dahi, is formed during the slow lactic fermentation of lactose from milk by thermophilic lactic acid bacteria (LAB). Thirty-five samples of yoghurt and curd were collected from the Biratnagar and isolation and identification of bacteria were done by various microbiological techniques like MRS Agar inoculation, colony characteristics, microscopic and biochemical examination. A total of sixty-six strains of lactobacilli were isolated from curd and identification of strains was done by biochemical and carbohydrate utilization test. Lactobacillus bulgaricus, L. casei, L. fermentum, L. acidophilus, and Streptococcus thermophilus were identified from curd. pH of samples was between 3.0 to 4.0 for homemade dahi; while 4.34 to 4.5 for commercially available yoghurt. The mean colony count of lactic acid bacteria was 1.4x107–4.9x107 cfu/g. 37.9% of samples contained Streptococcus thermophilus, 30.3% had Lactobacillus bulgaricus. Forty-five isolates from 24 industrial yoghurt samples showed 37.5% of the yoghurt contained both Lactobacillus bulgaricus and Streptococcus thermophilus followed by 25% samples having S. thermophilus and L. acidophilus. Other species like L. fermentum and L. casei were less common. From 11 homemade dahi samples, 54.5% of curd possessed both S. thermophilus and L. bulgaricus; 18.2% curd had both S. thermophilus and L. fermentum. The study concludes that L. bulgaricus and Streptococcus thermophilus are prevalent potent lactic acid bacteria. This study provides an account of the diversity of lactic acid bacteria in dahi/ yoghurt which will provide useful information about the variable nature of curd in this region to future researchers.

Lactic acid bacteria diversity in corn silage produced in Minas Gerais (Brazil)

PurposeThe diversity of lactic acid bacteria (LAB) in silages produced in warm climate countries is not well known. This study aimed to identify and characterise the metabolic and genotypic aspects of autochthonous LAB isolated from corn silage produced in the state of Minas Gerais, Brazil.MethodsEighty-eight LAB were isolated. To evaluate their performance at the strain level, all isolates were distinguished among strains using random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) and repetitive extragenic palindromic PCR (REP-PCR) techniques. The organic acid and ethanol production were determined by high-performance liquid chromatography (HPLC).ResultThe fingerprints obtained by RAPD-PCR with a M13 primer were more discriminatory than those obtained with the REP-PCR technique using a (GACA)4 primer. Moreover, 28 representative isolates were identified as Lactobacillus acidophilus, L. buchneri, L. casei, L. diolivorans, L. hilgardii, L. paracasei, L. parafarraginis, L. plantarum, L. rhamnosus, L. zeae and Pediococcus acidilactici. Different fingerprinting profiles between isolates within the same species were observed. However, some strains isolated from different silages showed the same band profile, thus suggesting the presence of clusters with high similar fingerprints in silages from various regions.ConclusionA variation in LAB diversity was observed in the silages of the evaluated regions, with L. rhamnosus and L. buchneri showing the highest distribution. Differences in organic acid production were observed among the strains belonging to the same species. This research contributes to a better understanding of the LAB community present in corn silage produced in warm climates. These strains will be studied as potential silage starters.

Application of cultivable lactic acid bacteria isolated from Iranian traditional dairy products for the production of liquid and dried kashks

This study was aimed to produce liquid and dried kashk as a traditional dairy-based product on an industrial scale. Furthermore, the microbial, chemical properties as well as the proximate composition including pH, moisture, salt, fat, protein, total volatile nitrogen (TVN) and peroxide value (PV) were assessed after 1, 10 and 20 days of cold storage (7 °C). Also, the samples from traditional dairy products such as yogurt, doogh, dried kashk, and lolek were collected, and the diversity of lactic acid bacteria (LAB) was determined as L. lactis subsp cremoris, Streptococcus thermophilus, L. lactis subsp lactis, Lactobacillus plantarum, Lactobacillus helveticus, Lactobacillus bulgaricus, Lactobacillus casei, and Lactobacillus fermentum. The mean values of fat, protein, and TVN for dried and liquid kashk samples were measured as (7.4 ± 0.7, 2.7 ± 0.1%), (51 ± 3.8, 8.7 ± 0.6 g/100 g) and (15.3 ± 3.9, 14.9 ± 4.1 mg/100 g), respectively. The microbial analysis revealed yeasts and molds were the most prevalent microorganisms in both types of kashks, while no Coliform, Escherichia coli, and Staphylococcus aureus bacteria were found in all samples. In conclusion, the selected species from traditional products which presented a specific property may provide a wide range of genetic variants to design modified species with desired characteristics.

Weissella, a novel lactic acid bacteria isolated from wild Sumatran orangutans (Pongo abelii).

Aims:This study aimed to isolate and identify lactic acid bacteria (LAB) in wild Sumatran orangutans to provide more information about LAB diversity derived from Sumatran orangutan feces.Materials and Methods:Fecal sampling from three female orangutans, around 35 years old, was carried out in the wild forest areas at the research station of Suaq Belimbing Gunung Leuser National Park located in the South Aceh district. Orangutan fecal samples were taken in the morning when the orangutans first defecated. The orangutans were above the tree, which is approximately 12-15 m from the ground where feces were found.Results:Fermentation testing using the API 50 CHL Kit showed that OUL4 isolates were identified as Lactococcus lactis ssp. lactis with an identity value of 73.5%. Homology analysis demonstrated that the OUL4 isolates have 93% similarity to Weissella cibaria, and phylogenetic trees constructed using Mega 7.0 also showed that OUL4 isolates are related to W. cibaria.Conclusion:These results show that there is a difference in identification between biochemical testing with API kits and molecular analyses on LAB isolates from wild Sumatran orangutans. Based on 16S rRNA gene homology, the OUL4 LAB isolates from wild Sumatran orangutans have 93% homology to W. cibaria.

Establishment Limitation Constrains the Abundance of Lactic Acid Bacteria in the Napa Cabbage Phyllosphere.

Patterns of phyllosphere diversity have become increasingly clear with high-throughput sequencing surveys, but the processes that control phyllosphere diversity are still emerging. Through a combination of lab and field experiments using Napa cabbage and lactic acid bacteria (LAB), we examined how dispersal and establishment processes shape the ecological distributions of phyllosphere bacteria. We first determined the abundance and diversity of LAB on Napa cabbage grown at three sites using both culture-based approaches and 16S rRNA gene amplicon sequencing. Across all sites, LAB made up less than 0.9% of the total bacterial community abundance. To assess whether LAB were low in abundance in the Napa cabbage phyllosphere due to a limited abundance in local species pools (source limitation), we quantified LAB in leaf and soil samples across 51 vegetable farms and gardens throughout the northeastern United States. Across all sites, LAB comprised less than 3.2% of the soil bacterial communities and less than 1.6% of phyllosphere bacterial communities. To assess whether LAB are unable to grow in the phyllosphere even if they dispersed at high rates (establishment limitation), we used a gnotobiotic Napa cabbage system in the lab with experimental communities mimicking various dispersal rates of LAB. Even at high dispersal rates, LAB became rare or completely undetectable in experimental communities, suggesting that they are also establishment limited. Collectively, our data demonstrate that the low abundance of LAB in phyllosphere communities may be explained by establishment limitation.IMPORTANCE The quality and safety of vegetable fermentations are dependent on the activities of LAB naturally present in the phyllosphere. Despite their critical role in determining the success of fermentation, the processes that determine the abundance and diversity of LAB in vegetables used for fermentation are poorly characterized. Our work demonstrates that the limited ability of LAB to grow in the cabbage phyllosphere environment may constrain their abundance on cabbage leaves. These results suggest that commercial fermentation of Napa cabbage proceeds despite low and variable abundances of LAB across different growing regions. Propagule limitation may also explain ecological distributions of other rare members of phyllosphere microbes.

Diversity of lactic acid bacteria in dadih produced by either back-slopping or spontaneous fermentation from two different regions of West Sumatra, Indonesia.

Aim:Dadih samples from two different origins (Kamang and Gadut in West Sumatra) manufactured with different methods (back-slopping or spontaneous fermentation) were evaluated for the diversity of lactic acid bacteria (LAB).Materials and Methods:Four dadih samples manufactured with two different fermentation methods were obtained from Kamang and Gadut regions. Both genotypic and phenotypic characteristic (16S rRNA partial gene sequence analysis and carbohydrate fermentation profile) were used to analyze the diversity of dadih LAB population.Results:This study showed that LAB count in back-slopping fermented dadih was one log cycle higher than spontaneous fermented dadih. LAB isolates from the two regions were divided into three genera, namely Lactococcus, Lactobacillus, and Pediococcus. Sequencing results showed that 41.6% (five isolates) were identified as Lactococcus lactis ssp. lactis, 25% (three isolates) were identified as Lactobacillus plantarum ssp. plantarum, 16.6% (two isolates) were identified as L. lactis ssp. cremoris, and 8.3% (one isolate each) were identified as Pediococcus pentosaceus and Lactobacillus pentosus.Conclusion:Five species were determined in back-slopping fermented dadih, i.e., L. lactis ssp. lactis, L. lactis ssp. cremoris, L. plantarum ssp. plantarum, L. pentosus, and P. pentosaceus. On the other hand, spontaneous fermented dadih only contained three different species, namely L. lactis ssp. lactis, L. lactis ssp. cremoris, and L. plantarum ssp. plantarum. This research showed that back-slopping fermentation offers greater abundance and diversity compared to spontaneous fermentation in dadih.

Short communication: Enzymatic perspective of galactosidases reveals variations in lactose metabolism among Lactococcus lactis strains

To date, most studies of lactose utilization have focused on the genetic diversity of lactic acid bacteria or its influence on product quality, but phenotypic evaluation has rarely been based on metabolic characteristics. In the present study, we investigated the growth, acid production, β-galactosidase, and 6-phospho-β-galactosidase activities of 16 Lactococcus lactis strains obtained from various habitats with lactose as the sole carbon source. The 15 L. lactis strains obtained from various habitats exhibited significant differences in growth and acid production characteristics in the de Man, Rogosa, and Sharpe-lactose broth, and 4 strains consumed more lactose when cultured in skim milk than the type strain ATCC 19435. Among these strains, DQHXNQ38-12 mainly produced acetoin and diacetyl when cultured in skim milk, whereas the strains 15M2 and 5G2 produced high levels of acid and formed curd rapidly. We concluded that the use of lactose is necessary for strain adaptation to the dairy niche. Comprehensive studies of lactose use and the fermentation characteristics of L. lactis are of significant importance.

Biodiversity and Multifunctional Features of Lactic Acid Bacteria Isolated From Table Olive Biofilms.

In the present study, a total of 554 lactic acid bacteria (LAB) isolates were obtained from the olive surface of Manzanilla, Gordal, and Aloreña cultivars processed as green Spanish-style or directly brined (natural) olives. The isolates obtained from industrial processes were genotyped by rep-PCR with primer GTG5, collecting a total of 79 different genotypes. The α-biodiversity indexes showed that the LAB diversity was higher in the biofilms on the fruits which followed the Spanish-style process than in those just brined. Sixteen genotypes had a frequency higher >1% and were identified, by multiplex PCR recA gene and 16S gene sequencing, as belonging to Lactobacillus pentosus (n = 13) and Lactobacillus plantarum (n = 3) species. A multivariate analysis based on a dataset with 89,744 cells, including technological (resistance to salt and pH, production of lactic acid, auto and co-aggregation with yeast species, β-glucosidase and esterase activities), and potential probiotic characteristics (survival to gastric and pancreatic digestions, resistance to antibiotics, inhibition of pathogens, presence of bsh genes, cholesterol removal, hemolytic, α-glucosidase, β-galactosidase, and phytase activities) showed that the 16 genotypes could be grouped into 3 great phenotypes. Thus, the genotype biodiversity in table olive biofilms was limited but, at phenotype level, it was even lower since L. pentosus predominated clearly (80.15% isolates). L. pentosus Lp13 was the genotype with the most promising characteristics for its use as a multifunctional starter, with this strain being and ubiquitous microorganism present in both natural and lye-treated olive fermentations.