Biological Transformation of Zearalenone by Some Bacterial Isolates Associated with Ruminant and Food Samples

Zearalenone (ZEA) is a secondary metabolite produced by Fusarium spp., the filamentous fungi. Food and feed contamination with zearalenone has adverse effects on health and economy. ZEA degradation through microorganisms is providing a promising preventive measure. The current study includes isolation of 47 bacterial strains from 100 different food and rumen samples. Seventeen isolates showed maximum activity of ZEA reduction. A bacterial isolate, RS-5, reduced ZEA concentration up to 78.3% through ELISA analysis and 74.3% as determined through HPLC. Ten of the most efficient strains were further selected for comparison of their biodegradation activity in different conditions such as incubation period, and different growth media. The samples were analyzed after 24 hrs, 48 hrs, and 72 hrs of incubation. De Man Rogosa Sharp (MRS) broth, Tryptic soy broth, and nutrient broth were used as different carbon sources for comparison of activity through ELISA. The mean degradation % ± SD through ELISA and HPLC were 70.77% ± 3.935 and 69.11% ± 2.768, respectively. Optimum reducing activity was detected at 72 hrs of incubation, and MRS broth is a suitable medium. Phylogenetic analysis based on 16S rRNA gene nucleotide sequences confirmed that one of the bacterial isolate RS-5 bacterial isolates with higher mycotoxin degradation is identified as Bacillus subtilis isolated from rumen sample. B05 (FSL-8) bacterial isolate of yogurt belongs to the genus Lactobacillus with 99.66% similarity with Lactobacillus delbrukii. Similarly, three other bacterial isolates, D05, H05 and F04 (FS-17, FSL-2 and FS-20), were found to be the sub-species/strains Pseudomonas gessardii of genus Pseudomonas based on their similarity level of (99.2%, 96% and 96.88%) and positioning in the phylogenetic tree. Promising detoxification results were revealed through GC-MS analysis of RS-5 and FSL-8 activity.

Isolasi Lactobacillus sp dari susu segar kemasan dan uji antimikroba terhadap bakteri patogen Salmonella sp dan Streptococcus mutan

Nilai gizi yang tinggi pada susu merupakan media yang baik untuk pertumbuhan berbagai macam mikroorganisme, baik yang menguntungkan maupun yang dapat membahayakan manusia. Penelitian ini bertujuan menganalisis kemampuan Lactobacillus sp yang diisolasi dari susu segar terhadap bakteri patogen Gram (+) dan Gram (-) yaitu Salmonella sp, Streptococcus mutan secara in vitro. Hasil penelitian menunjukkan total populasi BAL pada susu segar kemasan adalah 200x108 CFU/g. Pada pewarnaan Gram menujukkan hasil pewarnaan Gram yang positif, sedangkan pada uji katalase menjukkan reaksi yang negatif dan uji aktivitas antimikroba yang menggunakan metode difusica kram MRS broth. Susu segar kemasan mampu menghambat Salmonella sp dengan zona hambat tertinggi adalah 11,925 mm sedangkan pada Streptococcus mutans mampu menghambat dengan zona tertinggi yaitu 13,45 mm.

Biomodification of acenocoumarol by bifidobacteria

ABSTRACT The increased interest of consumers in probiotic foods requires a deeper knowledge on the possible interactions with drugs, because their pharmacological properties could be modified. In this context, these studies are relevant for drugs such as acenocoumarol, whose dosage must be controlled due to, among other factors, food-drug interactions. Acenocoumarol is an oral anticoagulant with a narrow therapeutic range. The aim of the present research is to evaluate, in vitro, the effect of bifidobacteria on acenocoumarol. The drug was incubated with Bifidobacterium bifidum CIDCA 5310 or Bifidobacterium adolescentis CIDCA 5317 in MRS broth at 37°C for 24 h in anaerobic conditions. The effect of incubation with sterilized spent culture supernatants (SSCS) was also evaluated. Analysis by RP-HPLC showed that both bifidobacterial strains reduced the area of the acenocoumarol peak and two new peaks were evidenced. In addition, a decrease in the intensity of the bands at 1650, 1390 and 1110/cm was observed in the FTIR spectroscopic determinations. Moreover, a new band appeared at 1720/cm. No effect on the drug was observed when incubation was performed with SSCS. The present study showed a significant change in the concentration of the anticoagulant after incubation with bifidobacteria and results are compatible with biomodification of the drug due to enzymatic activity of bifidobacteria.

Assessment of the viability of cultures of lactic acid microorganisms during their freezing and low-temperature storage

Relevance. A significant increase in microbiome-associated diseases, closely related to violations of the bacterial diversity and functions of the normal intestinal microbiota, dictates the need to develop and implement measures for the long-term preservation of individual representatives of the normal microbiota in order to create new strategies for modifying the composition of microbiomes.Methods. The influence of the technology of deep freezing and storage of intestinal isolates of lactic acid bacteria of 2 taxonomic groups isolated from poultry in the conditions of the Low-temperature automated storage of biological samples of the Departmental Collection of useful microorganisms for Agricultural purposes of the Russian Agricultural Academy (VKSM) on the MRS culture medium using 10 and 20% glycerin or 10 and 20% sucrose as cryopreservants was studied. The suspensions of the isolates were frozen at - 150 °C for 18 hours and then placed in an automated cryopreservation at -80 °C. Control of samples for safetyResults. The technology of cryofreezing of lactic acid bacteria on MRS-broth using 10 and 20% glycerin or 10 and 20% sucrose as cryopreservants allows preserving the viability, physiological and biochemical properties of intestinal isolates of lactic acid bacteria when stored for 18 months. All the protective media used (MRS-broth with glycerin 10 and 20%, MRS -broth with sucrose 10 and 20%) showed comparable results in the preservation of viability and acid-forming activity of Lactobacillus fermentum-2, Pediococcus pentosaceus 6p-3, Pediococcus pentosaceus 28p-1 isolates. Then the storage of Pediococcus pentosaceus isolate (28p-1) in a given parameter on a protective medium with 10 and 20% sucrose led to a decrease in the activity of acid formation.

Production of Phenyllactic Acid from Porphyra Residues by Lactic Acid Bacterial Fermentation

The concept of algae biorefinery is attracting attention because of the abundant valuable compounds within algal biomass. Phenyllactic acid (PhLA), a broad-spectrum antimicrobial organic acid that can be produced by lactic acid bacteria (LAB), is considered a potential biopreservative. In this study, a cascading biorefinery approach was developed to harvest PhLA from Porphyra residues by LAB fermentation. LAB strains were cultivated in de Man, Rogosa and Sharpe (MRS) broth to screen their ability to produce PhLA. As the strains of Lactobacillus plantarum KP3 and L. plantarum KP4 produced higher concentrations of PhLA at 0.09 mg/mL, these two strains were employed for fermentation. After phycobiliprotein extraction, the Porphyra residues, ultrafiltration eluate, phenylalanine (Phe) and yeast extract with a volume of 20 mL were inoculated with LAB strain KP3 and fermented at 37 °C for 120 h. The PhLA content of the fermented broth was 1.86 mg. To optimize the biorefinery process, the ultrafiltration eluate was replaced by commercial cellulase. Up to 4.58 mg of PhLA, which was 2.5 times greater than that produced from KP3 cultured in MRS broth, could be harvested. Taken together, the findings provide an optimized process for LAB fermentation, which is shown to be a feasible algae biorefinery approach to obtaining PhLA from Porphyra residues.

Isolation, identification and investigation some biochemical properties of lactic acid bacteria from “Mam sac chua” and “Com me” in Tien Giang province

The objective of this study was isolate, identify and investigate some biochemical properties of strains of lactic acid bacteria from “com me” and “mam sac chua” in Tien Giang province. Nineteen strains of LAB were isolated from four “com me” and three “mam sac chua” samples. They have characterized of lactic acid bacteria such as: halo rings in MRS agar environment added 0,85% CaCO3, rod-shaped cells, Gram positive, catalate and oxidase negative. All 19 strains of LAB were able to produce lactic acid in MRS broth (1,01 – 2,23 mg/ mL after 24 hours). Three strains of LAB were isolated from “com me” were able to produce lactic acid in MRS broth at salt concentration of 0, 2, 4 and 6% (0,57 – 1,29 mg/ mL after 24 hours). In particular, strains of LAB were coded ML3 and ML4 produced the highest lactic acid and VB strain was the most salinity tolerance. Therefore, these three srains were choosed to identify species by molecular biology technique. The results of identification were Staphylococcus piscifermentans VB, Lactobacillus plantarum ML3 and Lactobacillus plantarum ML4 because they are 99% homologous to S. piscifermentans and L. plantarum.

IDENTIFIKASI DAN KARAKTERISASI BAKTERI ASAM LAKTAT PADA ACAR KETIMUN (Cucumis sativus L.) SEBAGAI AGENSI PROBIOTIK

Di Indonesia terkenal dengan berbagai macam makanan tradisional fermentasi. Jenis makanan tradisional yang banyak dijumpai yang diproses dengan menggunakan proses fermentasi adalah tape, asinan, acar dan lainnya yang mengandung banyak bakteri asam laktat (BAL). Bakteri asam laktat ini merupakan kekayaan alam mikroba yang masih harus dieksplorasi dibidang kesehatannya. Penelitian ini bertujuan untuk mengetahui jenis-jenis dan karakteristik bakteri asam laktat yang terdapat pada acar ketimun. Penelitian ini menggunakan metode deskriptif. Teknik pengambilan sampel langsung dilakukan secara aseptis. Bahan yang digunakan adalah bakteri asam laktat yang diambil dari cairan acar ketimun dengan variasi isi ketimun, ketimun nenas, ketimun nenas dan cabai dan ditumbuhkan pada media MRS Broth (de Man Rogosa Sharpe). Berdasarkan hasil penelitian identifikasi dan karakterisasi bakteri asam laktat pada acar ketimun dengan menggunakan uji morfologi, pewarnaan gram dan uji biokimia maka diperoleh 2 jenis bakteri asam laktat pada acar ketimun. Adapun bakteri asam laktat yang ditemukan antara lain adalah Lactobacillus plantarum dan Lactobacillus reuteri. Karakterisitik secara umum adalah basil, gram positif, katalase negatif, tidak motil, suhu optimum 250°C- 300°C dan memiliki tipe fermentasi heterofermentatif dan homofermentatif. ABSTRACT: In Indonesia it is famous for various kinds of traditional fermented foods. Traditional food types that are often found that are processed using fermentation are tape, pickled, pickled and others that contain a lot of lactic acid bacteria (LAB). This lactic acid bacteria is a natural wealth of microbes that must still be explored in the field of health. This study aims to determine the types and characteristics of lactic acid bacteria found in pickles to Cucumber. This research uses a descriptive method. The direct sampling technique is carried out aseptically. The material used is lactic acid bacteria taken from pickled liquid to Cucumber with various contents to Cucumber, to Pineapple Cucumber, to Cucumber pineapple and chili and grown on MRS Broth media (de Man Rogosa Sharpe). Based on the results of the study of identification and characterization of lactic acid bacteria on pickles to Cucumber using morphological tests, gram staining and biochemical tests, 2 types of lactic acid bacteria were obtained on pickles to Cucumber. The lactic acid bacteria found include Lactobacillus plantarum and Lactobacillus reuteri. General characteristics are basil, gram positive, negative catalase, not motile, optimum temperature 250C-300C and have heterofermentative and homofermentative fermentation types. Keywords: Lactic acid bacteria, Probiotik, Pickled cucumber

Effect of Cocultivation on Lactobacillus plantarum Strains Growth and Antagonistic Activity

The use of bacterial starters for the production of fermented foods has several advantages over traditional spontaneous fermentation, as it provides a rapid and controlled decrease of pH, improves the microbiological quality of the product, and prolongs the shelf-life. Fermented foods are typically produced using mixed cultures of lactic acid bacteria (LAB) due to the synergism between their constituent bacterial cultures. So, the compatibility of the LAB strains decides the efficacy of a multi-strain starter. The purpose of this study was to investigate the effect of the cocultivation of Lactobacillus plantarum strains on the growth, acidification, and antagonistic activity to determine suitable strain combinations for fermented vegetable production. Methods. The effect of cocultivation on growth characteristics of four L. plantarum strains was determined in MRS medium and cabbage-based medium with 2.5% NaCl. After 8 h of cultivation at 30°C and 37°C, the number of viable cells (CFU/ml) and the pH of the medium were determined. The antagonistic activity of monocultures of L. plantarum and their six compositions against opportunistic pathogenic microorganisms was determined by the method of delayed antagonism. Results. During growth in MRS broth at 30°C cocultivation of L. plantarum 47SM with L. plantarum 691T or L. plantarum 1047K strains led to enhanced rates of growth compared to the monocultures, suggesting some degree of symbiosis between these strains. Viable cell counts of L. plantarum 47SM, 1047K and 691T strains and ΔpH values of L. plantarum 952K, 1047K, and 691T strains were higher after 8 h growth in the cabbage-based medium at 30°C compared to MRS broth. Despite the intensive growth of L. plantarum monocultures in cabbage-based medium, a significant decrease of viable cell counts and ΔpH values during cocultivation at 30°C were found. Cocultivation did not affect the average size of the growth inhibition zones of most of the indicator strains used. However, growth inhibition zones of Shigella flexneri, Escherichia coli, and Proteus vulgaris decreased in some L. plantarum mixed cultures compared to monocultures. Thus, the growth inhibition zones of E. coli and S. flexneri by mixed culture L. plantarum 47 SM+1047K were significantly smaller compared to the growth inhibition zones of L. plantarum monocultures. Conclusions. Thus, based on the data obtained in present work, we can assume that some of these L. plantarum strains used in the work may be bactericinogenic. Although the four L. plantarum strains studied are compatible when cocultivated in a standard rich MRS medium, the results of cocultivation in a cabbage-based medium with 2.5% NaCl does not allow to recommend the use of these L. plantarum strains simultaneously in the starter for vegetable fermentation. Further investigation of bacteriocinogenic properties and mechanisms of growth inhibition under cocultivation in vegetable-like conditions are needed, which will allow combining of some of these L. plantarum strains with LAB strains of other species or genera to create multi-starters for vegetable fermentation.

Extraction and Isolation of Antioxidant-antibacterial Compounds From Lactobacillus casei Strain K1C by Thin-layer Chromatography

Background: Nowadays, searching for natural bioactive compounds with potential use in food industries is a major issue. Because of simple purification, natural compounds from microbial sources attract more attention. These encompass antioxidant and antibacterial materials derived from probiotics. Methods: In this study, Lactobacillus strains were isolated from kefir specimens. The antioxidant and antibacterial activity of the methanol extract of the supernatants was determined using 2, 2-diphenyl-picyril hydrazil (DPPH) and minimum inhibitory concentration (MIC) methods, respectively. In order to increase the antioxidant properties, a minimum medium fermented aerobically was used. Results: Antibacterial activity of Lactobacillus supernatant increased against E. coli ATCC 11303 in case of minimum medium (25.32 mg/mL) compared to MRS broth (32 mg/mL); however, aerobic condition decreased antibacterial production (65.44 mg/mL). After fractionation by thin-layer chromatography (TLC), this value reached the highest level (500 µg/mL). Production analysis at different times showed that maximum antibacterial activity was obtained in the middle of the logarithmic growth phase until the beginning of the stationary growth phase. The antioxidant traits increased significantly in minimum culture media and anaerobic condition (492.1 ± 0.25 µg/mL) compared to the similar condition in MRS broth (880.96 ± 0.05 µg/mL). The highest antioxidant production was observed in the stationary growth phase of the aerobically fermented minimum medium (266.82 ± 0.17 µg/mL). Conclusions: The findings of this study showed that the best antibacterial and antioxidant-producing isolate, L. casei strain K1C (accession no.: KU954559), could be useful as a natural preservative in food industries.

Aflatoxin B1 and Sterigmatocystin Binding Potential of Non-Lactobacillus LAB Strains

Research on the ability of lactic acid bacteria (LAB) to bind aflatoxin B1 (AFB1) has mostly been focusing on lactobacilli and bifidobacteria. In this study, the AFB1 binding capacities of 20 Enterococcus strains belonging to E. casseliflavus, E. faecalis, E. faecium, E. hirae, E. lactis, and E. mundtii, 24 Pediococcus strains belonging to species P. acidilactici, P. lolii, P. pentosaceus, and P. stilesii, one strain of Lactococcus formosensis and L.garviae, and 3 strains of Weissella soli were investigated in MRS broth at 37 °C at 0.2 µg/mL mycotoxin concentration. According to our results, among non-lactobacilli LAB, the genera with the best AFB1 binding abilities were genus Pediococcus, with a maximum binding percentage of 7.6% by P. acidilactici OR83, followed by genus Lactococcus. For AFB1 bio-detoxification purposes, beside lactobacilli, pediococci can also be chosen, but it is important to select a strain with better binding properties than the average value of its genus. Five Pediococcus strains have been selected to compare their sterigmatocystin (ST) binding abilities to AFB1 binding, and a 2–3-fold difference was obtained similar to previous findings for lactobacilli. The best strain was P. acidilactici OR83 with 18% ST binding capacity. This is the first report on ST binding capabilities of non-Lactobacillus LAB strains.