Ranjita Rai - Academia.edu (original) (raw)

Papers by Ranjita Rai

Research paper thumbnail of In vitro and genetic screening of probiotic properties of lactic acid bacteria isolated from naturally fermented cow-milk and yak-milk products of Sikkim, India

World Journal of Microbiology & Biotechnology, Jan 6, 2022

A total of 272 isolates of lactic acid bacteria (LAB) were isolated from 22 samples of naturally ... more A total of 272 isolates of lactic acid bacteria (LAB) were isolated from 22 samples of naturally fermented milk products of Sikkim in India viz. dahi , soft-variety chhurpi , hard-variety chhurpi , mohi and philu , out of which, 68 LAB isolates were randomly grouped on the basis of phenotypic characteristics, and were identified by 16S rRNA gene sequence analysis. Leuconostoc mesenteroides was the most dominant genus, followed by Leuc. mesenteroides subsp. jonggajibkimchii , Lactococcus lactis subsp. cremoris , Lc. lactis, Lc. lactis subsp. hordniae , Lc. lactis subsp. tructae , Enterococcus faecalis , E. italicus and E. pseudoavium . LAB strains were tested for probiotics attributes by in vitro and genetic screening, based on marker genes. LAB strains showed tolerance to pH 3.0, bile salt, resistance to lysozyme and β-galactosidase activity. Enterococcus faecalis YS4-11 and YS4-14 and Lactococcus lactis subsp. cremoris SC3 showed more than 85% of hydrophobicity. Genes clp L and tdc encoding for low pH tolerance, agu A and Ir1516 encoding for bile tolerance, LBA1446 gene encoding for BSH activity, map A , apf , mub 1 and msa encoding for mucosal binding property were detected. Gene mesY for bacteriocin production was detected only in Leuconostoc spp. Based on the in vitro and genetic screening of probiotic attributes, Leuc. mesenteroides ; Leuc. mesenteroides subsp. jonggajibkimchii and Lc. lactis subsp. cremoris were tentatively selected for possible probiotic candidates.

Research paper thumbnail of In vitro and genetic screening of probiotic properties of lactic acid bacteria isolated from naturally fermented cow-milk and yak-milk products of Sikkim, India

World Journal of Microbiology and Biotechnology, 2022

A total of 272 isolates of lactic acid bacteria (LAB) were isolated from 22 samples of naturally ... more A total of 272 isolates of lactic acid bacteria (LAB) were isolated from 22 samples of naturally fermented milk products of Sikkim in India viz. dahi , soft-variety chhurpi , hard-variety chhurpi , mohi and philu , out of which, 68 LAB isolates were randomly grouped on the basis of phenotypic characteristics, and were identified by 16S rRNA gene sequence analysis. Leuconostoc mesenteroides was the most dominant genus, followed by Leuc. mesenteroides subsp. jonggajibkimchii , Lactococcus lactis subsp. cremoris , Lc. lactis, Lc. lactis subsp. hordniae , Lc. lactis subsp. tructae , Enterococcus faecalis , E. italicus and E. pseudoavium . LAB strains were tested for probiotics attributes by in vitro and genetic screening, based on marker genes. LAB strains showed tolerance to pH 3.0, bile salt, resistance to lysozyme and β-galactosidase activity. Enterococcus faecalis YS4-11 and YS4-14 and Lactococcus lactis subsp. cremoris SC3 showed more than 85% of hydrophobicity. Genes clp L and tdc encoding for low pH tolerance, agu A and Ir1516 encoding for bile tolerance, LBA1446 gene encoding for BSH activity, map A , apf , mub 1 and msa encoding for mucosal binding property were detected. Gene mesY for bacteriocin production was detected only in Leuconostoc spp. Based on the in vitro and genetic screening of probiotic attributes, Leuc. mesenteroides ; Leuc. mesenteroides subsp. jonggajibkimchii and Lc. lactis subsp. cremoris were tentatively selected for possible probiotic candidates.

Research paper thumbnail of Metagenome gene prediction of naturally fermented milk products of India using PICRUSt2 and Piphillin

Background: Naturally fermented milk (NFM) products are popular food delicacies in Indian states ... more Background: Naturally fermented milk (NFM) products are popular food delicacies in Indian states of Sikkim and Arunachal Pradesh. Bacterial communities in these NFM products of India were previously analysed by high-throughput sequence method. However, predictive gene functionality of NFM products of India has not been studied. In this study, raw sequences of NFM products of Sikkim and Arunachal Pradesh were accessed from NCBI database server. PICRUSt2 and Piphillin tools were applied to study microbial functional gene prediction in combination with the commonly used error-corrected denoising programs like DADA2 and Deblur.Results: Significant functional hits were observed from the Piphillin analysis which included some interesting pathways including GABAergic synapse, glutamatergic synapse and serotonergic synapse, which are known to be probiotic-related, among others that are absent in PICRUSt2 analysis. This study also showed the negative correlation of lactic acid bacteria (LAB)...

Research paper thumbnail of Naturally fermented milk products of the Eastern Himalayas

Journal of Ethnic Foods, 2016

Background: Pastoralists comprising of different ethnic groups of people dominate The Eastern Him... more Background: Pastoralists comprising of different ethnic groups of people dominate The Eastern Himalayas. The traditional knowledge in the Eastern Himalayas reflects the common linkage of origin and settlement of the ethnic groups in the regions. The practice of milk fermentation stretches along the Eastern Himalaya regions show similar types of ethnic naturally fermented milk (NFM) products that are regularly prepared by different ethnic groups of people. Methods: Survey of various types of NFM products of Eastern Nepal, Darjeeling hills, Sikkim and Arunachal Pradesh in India, and Bhutan and their methods of preparation, mode of consumption and ethnical values were documented as per the standard method. Results: Sikkim and Nepal have several varieties of NFM product which includes dahi, mohi, gheu, soft-chhurpi, hard-chhurpi, dudh-chhurpi, chhu, somar, maa, philu and shyow. The main products, which are daily prepared in Arunachal Pradesh, are mar, chhurpi/churapi, churkam and churtang/chhurpupu. NFM products of Bhutan are dahi, datshi, mohi, gheu, chugo and hitpa. Conclusion: The unique types of NFM, though of minor products, but of high biological importance have been reported from the Eastern Himalayas.

Research paper thumbnail of Bacterial community in naturally fermented milk products of Arunachal Pradesh and Sikkim of India analysed by high-throughput amplicon sequencing

Scientific Reports, 2018

Naturally fermented milk (NFM) products are popular ethnic fermented foods in Arunachal Pradesh a... more Naturally fermented milk (NFM) products are popular ethnic fermented foods in Arunachal Pradesh and Sikkim states of India. The present study is the first to have documented the bacterial community in 54 samples of NFM products viz. chhurpi, churkam, dahi and gheu/mar by high-throughput Illumina amplicon sequencing. Metagenomic investigation showed that Firmicutes (Streptococcaceae, Lactobacillaceae) and Proteobacteria (Acetobacteraceae) were the two predominant members of the bacterial communities in these products. Lactococcus lactis and Lactobacillus helveticus were the predominant lactic acid bacteria while Acetobacter spp. and Gluconobacter spp. were the predominant acetic acid bacteria present in these products. Naturally fermented milk (NFM) products are prepared by one of the oldest processes of milk fermentation in the world using raw or boiled milk to ferment spontaneously or by back-sloping method 1. Some naturally fermented milk products are chhu, chhurpi, dahi, lassi, misti dahi, mohi, philu, shoyu, somar and srikhand (cow/buffalo/

Research paper thumbnail of Some Technological Properties of Lactic Acid Bacteria Isolated from Dahi and Datshi, Naturally Fermented Milk Products of Bhutan

Frontiers in Microbiology, 2017

Research paper thumbnail of HACCP model of kinema, a fermented soybean food

hazards and measures for their control to ensure the safety of foods. Kinema is a naturally ferme... more hazards and measures for their control to ensure the safety of foods. Kinema is a naturally fermented soybean food of the Eastern Himalayas. The present study on HACCP of kinema revealed that marketed kinema has higher microbial load as compared to the one prepared under laboratory condition and home-made kinema. Furthermore, the Critical Control Point (CCP) was checked during kinema preparation in both traditionally prepared method and kinema prepared under laboratory condition. HACCP model for optimised production of kinema has been proposed.

Research paper thumbnail of In vitro and genetic screening of probiotic properties of lactic acid bacteria isolated from naturally fermented cow-milk and yak-milk products of Sikkim, India

World Journal of Microbiology & Biotechnology, Jan 6, 2022

A total of 272 isolates of lactic acid bacteria (LAB) were isolated from 22 samples of naturally ... more A total of 272 isolates of lactic acid bacteria (LAB) were isolated from 22 samples of naturally fermented milk products of Sikkim in India viz. dahi , soft-variety chhurpi , hard-variety chhurpi , mohi and philu , out of which, 68 LAB isolates were randomly grouped on the basis of phenotypic characteristics, and were identified by 16S rRNA gene sequence analysis. Leuconostoc mesenteroides was the most dominant genus, followed by Leuc. mesenteroides subsp. jonggajibkimchii , Lactococcus lactis subsp. cremoris , Lc. lactis, Lc. lactis subsp. hordniae , Lc. lactis subsp. tructae , Enterococcus faecalis , E. italicus and E. pseudoavium . LAB strains were tested for probiotics attributes by in vitro and genetic screening, based on marker genes. LAB strains showed tolerance to pH 3.0, bile salt, resistance to lysozyme and β-galactosidase activity. Enterococcus faecalis YS4-11 and YS4-14 and Lactococcus lactis subsp. cremoris SC3 showed more than 85% of hydrophobicity. Genes clp L and tdc encoding for low pH tolerance, agu A and Ir1516 encoding for bile tolerance, LBA1446 gene encoding for BSH activity, map A , apf , mub 1 and msa encoding for mucosal binding property were detected. Gene mesY for bacteriocin production was detected only in Leuconostoc spp. Based on the in vitro and genetic screening of probiotic attributes, Leuc. mesenteroides ; Leuc. mesenteroides subsp. jonggajibkimchii and Lc. lactis subsp. cremoris were tentatively selected for possible probiotic candidates.

Research paper thumbnail of In vitro and genetic screening of probiotic properties of lactic acid bacteria isolated from naturally fermented cow-milk and yak-milk products of Sikkim, India

World Journal of Microbiology and Biotechnology, 2022

A total of 272 isolates of lactic acid bacteria (LAB) were isolated from 22 samples of naturally ... more A total of 272 isolates of lactic acid bacteria (LAB) were isolated from 22 samples of naturally fermented milk products of Sikkim in India viz. dahi , soft-variety chhurpi , hard-variety chhurpi , mohi and philu , out of which, 68 LAB isolates were randomly grouped on the basis of phenotypic characteristics, and were identified by 16S rRNA gene sequence analysis. Leuconostoc mesenteroides was the most dominant genus, followed by Leuc. mesenteroides subsp. jonggajibkimchii , Lactococcus lactis subsp. cremoris , Lc. lactis, Lc. lactis subsp. hordniae , Lc. lactis subsp. tructae , Enterococcus faecalis , E. italicus and E. pseudoavium . LAB strains were tested for probiotics attributes by in vitro and genetic screening, based on marker genes. LAB strains showed tolerance to pH 3.0, bile salt, resistance to lysozyme and β-galactosidase activity. Enterococcus faecalis YS4-11 and YS4-14 and Lactococcus lactis subsp. cremoris SC3 showed more than 85% of hydrophobicity. Genes clp L and tdc encoding for low pH tolerance, agu A and Ir1516 encoding for bile tolerance, LBA1446 gene encoding for BSH activity, map A , apf , mub 1 and msa encoding for mucosal binding property were detected. Gene mesY for bacteriocin production was detected only in Leuconostoc spp. Based on the in vitro and genetic screening of probiotic attributes, Leuc. mesenteroides ; Leuc. mesenteroides subsp. jonggajibkimchii and Lc. lactis subsp. cremoris were tentatively selected for possible probiotic candidates.

Research paper thumbnail of Metagenome gene prediction of naturally fermented milk products of India using PICRUSt2 and Piphillin

Background: Naturally fermented milk (NFM) products are popular food delicacies in Indian states ... more Background: Naturally fermented milk (NFM) products are popular food delicacies in Indian states of Sikkim and Arunachal Pradesh. Bacterial communities in these NFM products of India were previously analysed by high-throughput sequence method. However, predictive gene functionality of NFM products of India has not been studied. In this study, raw sequences of NFM products of Sikkim and Arunachal Pradesh were accessed from NCBI database server. PICRUSt2 and Piphillin tools were applied to study microbial functional gene prediction in combination with the commonly used error-corrected denoising programs like DADA2 and Deblur.Results: Significant functional hits were observed from the Piphillin analysis which included some interesting pathways including GABAergic synapse, glutamatergic synapse and serotonergic synapse, which are known to be probiotic-related, among others that are absent in PICRUSt2 analysis. This study also showed the negative correlation of lactic acid bacteria (LAB)...

Research paper thumbnail of Naturally fermented milk products of the Eastern Himalayas

Journal of Ethnic Foods, 2016

Background: Pastoralists comprising of different ethnic groups of people dominate The Eastern Him... more Background: Pastoralists comprising of different ethnic groups of people dominate The Eastern Himalayas. The traditional knowledge in the Eastern Himalayas reflects the common linkage of origin and settlement of the ethnic groups in the regions. The practice of milk fermentation stretches along the Eastern Himalaya regions show similar types of ethnic naturally fermented milk (NFM) products that are regularly prepared by different ethnic groups of people. Methods: Survey of various types of NFM products of Eastern Nepal, Darjeeling hills, Sikkim and Arunachal Pradesh in India, and Bhutan and their methods of preparation, mode of consumption and ethnical values were documented as per the standard method. Results: Sikkim and Nepal have several varieties of NFM product which includes dahi, mohi, gheu, soft-chhurpi, hard-chhurpi, dudh-chhurpi, chhu, somar, maa, philu and shyow. The main products, which are daily prepared in Arunachal Pradesh, are mar, chhurpi/churapi, churkam and churtang/chhurpupu. NFM products of Bhutan are dahi, datshi, mohi, gheu, chugo and hitpa. Conclusion: The unique types of NFM, though of minor products, but of high biological importance have been reported from the Eastern Himalayas.

Research paper thumbnail of Bacterial community in naturally fermented milk products of Arunachal Pradesh and Sikkim of India analysed by high-throughput amplicon sequencing

Scientific Reports, 2018

Naturally fermented milk (NFM) products are popular ethnic fermented foods in Arunachal Pradesh a... more Naturally fermented milk (NFM) products are popular ethnic fermented foods in Arunachal Pradesh and Sikkim states of India. The present study is the first to have documented the bacterial community in 54 samples of NFM products viz. chhurpi, churkam, dahi and gheu/mar by high-throughput Illumina amplicon sequencing. Metagenomic investigation showed that Firmicutes (Streptococcaceae, Lactobacillaceae) and Proteobacteria (Acetobacteraceae) were the two predominant members of the bacterial communities in these products. Lactococcus lactis and Lactobacillus helveticus were the predominant lactic acid bacteria while Acetobacter spp. and Gluconobacter spp. were the predominant acetic acid bacteria present in these products. Naturally fermented milk (NFM) products are prepared by one of the oldest processes of milk fermentation in the world using raw or boiled milk to ferment spontaneously or by back-sloping method 1. Some naturally fermented milk products are chhu, chhurpi, dahi, lassi, misti dahi, mohi, philu, shoyu, somar and srikhand (cow/buffalo/

Research paper thumbnail of Some Technological Properties of Lactic Acid Bacteria Isolated from Dahi and Datshi, Naturally Fermented Milk Products of Bhutan

Frontiers in Microbiology, 2017

Research paper thumbnail of HACCP model of kinema, a fermented soybean food

hazards and measures for their control to ensure the safety of foods. Kinema is a naturally ferme... more hazards and measures for their control to ensure the safety of foods. Kinema is a naturally fermented soybean food of the Eastern Himalayas. The present study on HACCP of kinema revealed that marketed kinema has higher microbial load as compared to the one prepared under laboratory condition and home-made kinema. Furthermore, the Critical Control Point (CCP) was checked during kinema preparation in both traditionally prepared method and kinema prepared under laboratory condition. HACCP model for optimised production of kinema has been proposed.