Tanzina, A. Y. | Search bioRxiv

bioRxiv2021

Insights into the nutritional properties and microbiome diversity in sweet and sour yogurt manufactured in Bangladesh

Yogurt quality mainly depends on nutritional properties, microbial diversity and purity of starter culture. This study aimed to assess the nutritional composition and microbiome diversity in yogurt. Microbial diversity was analyzed by 16S and 18S rRNA based high-throughput sequencing. Significantly (P<0.05) higher pH, fat, moisture, total solid and solid-non-fat contents (%) were observed in sweet yogurt whereas sour varieties had significantly higher ash and minerals. Metagenomic investigation showed that 44.86% and 55.14% reads were assigned to bacterial and fungal taxa, respectively, with significantly higher taxonomic richness in sour yogurt. A significant difference in bacterial (Ppermanova=0.001) and fungal (Ppermanova=0.013) diversity between sweet and sour yogurt was recorded. We detected 76 bacterial and 70 fungal genera across these samples which were mostly represented by Firmicutes (>92%) and Ascomycota (98%) phyla, respectively. Among the detected genera, 36.84% bacterial and 22.86% fungal genera were found in both yogurt types. Our results suggest that Streptococcus (50.82%), Lactobacillus (39.92%), Enterobacter (4.85%), Lactococcus (2.84%) and Aeromonas (0.65%) are the most abundant bacterial genera, while Kluyveromyces (65.75%), Trichosporon (8.21%), Clavispora (7.19%), Candida (6.71%), Iodophanus (2.22%), Apiotrichum (1.94%), and Issatchenkia (1.35%) are the most abundant fungal genera in yogurt metagenomes. This is the first study on nutritional properties and microbiome diversity of Bangladeshi yogurt that would be a benchmark for safe production of quality yogurt by commercial manufacturers.

microbiology↗

bioRxiv2020

Exploring the genomic and proteomic variations of SARS-CoV-2 spike glycoprotein: a computational biology approach

The newly identified SARS-CoV-2 has now been reported from around 183 countries with more than a million confirmed human cases including more than 68000 deaths. The genomes of SARS-COV-2 strains isolated from different parts of the world are now available and the unique features of constituent genes and proteins have gotten substantial attention recently. Spike glycoprotein is widely considered as a possible target to be explored because of its role during the entry of coronaviruses into host cells. We analyzed 320 whole-genome sequences and 320 spike protein sequences of SARS-CoV-2 using multiple sequence alignment tools. In this study, 483 unique variations have been identified among the genomes including 25 non-synonymous mutations and one deletion in the spike protein of SARS-CoV-2. Among the 26 variations detected, 12 variations were located at the N-terminal domain and 6 variations at the receptor-binding domain (RBD) which might alter the interaction with receptor molecules. In addition, 22 amino acid insertions were identified in the spike protein of SARS-CoV-2 in comparison with that of SARS-CoV. Phylogenetic analyses of spike protein revealed that Bat coronavirus have a close evolutionary relationship with circulating SARS-CoV-2. The genetic variation analysis data presented in this study can help a better understanding of SARS-CoV-2 pathogenesis. Based on our findings, potential inhibitors can be designed and tested targeting these proposed sites of variation.

bioinformatics↗