Background: The constant global need for food has created a demand for colossal food production. Every day the world requires more food than it is capable of growing and harvesting. Antibiotics have been used in healthy food products to promote growth and prevent disease in food-producing animals for a long time. This prolonged use of antibiotics leads to the development of resistant bacteria and the accumulation of antibiotic residue in livestock and fish. To avoid further causalities finding an effective alternative became a dire need. At present, the most suitable alternative for antibiotics is probiotics. Main body: Probiotics are live microorganisms that provide health benefits when consumed or applied to the body with the optimum amount. Probiotics are mainly good bacteria and yeast which fight off the pathogenic bacteria, improve the immune system, and restore the gut microbial balance. Probiotics can eliminate the harmful pathogens following several molecular mechanisms and modulate the immune response of the host animal for the well-being of the animals. This review article aims to describe probiotics as a potential growth promoter in major food sectors (poultry, ruminant, and aquaculture), how probiotics can ensure food safety without harmful effects on animals, and find out some points where more research is required to ensure a positive outcome. Conclusion: The conclusion of this review article highlights the knowledge gaps and how they can be minimized using modern molecular technologies to establish probiotic supplements as an effective alternative to antibiotics.

Budding yeast, Saccharomyces cerevisiae, is an ideal model organism for genetic research due to its similarity in life cycle and cellular structure to higher eukaryotes as well as its ease of cultivation and manipulation in the laboratory. Yeast cells benefit from being cultured in calorie-restricted media, which can be achieved by reducing glucose concentration from 2 % to 0.5 %. Cell metabolism depends on glucose and therefore, affects the physiology of the cell. This study aimed to investigate the effects of long-term glucose starvation on the lifespan of yeast cells by culturing in both standard and glucose-starved conditions. In this investigation yeast cells (BY4743 strain) were cultured in glucose-restricted YPD media (0.5 percent dextrose) to assess lifespan, growth-proliferation, autophagy, apoptosis, mtDNA abundance. The findings revealed that prolonged glucose restriction significantly extended chronological lifespan in yeast (p < 0.05). In order to decipher how starved yeast live chronologically longer, we tested mitochondrial association and found that calorie deprivation lowered the rate of mtDNA spontaneous mutation and increased mtDNA abundance which is a suggestive sign of mitobiogenesis. Furthermore, cells cultured on glucose-restricted media led to more autophagosome formation but less cell death. These results suggested that glucose restriction can enhance lifespan by improving overall cellular conditions. These findings may serve as a foundation for future research in aging, cancer and diabetes.

Climate change is responsible to a certain extent for the occurrence and spread of arboviral pathogens worldwide. Temperature is one of the crucial abiotic factors influencing the physiological processes of mosquitoes. Several genes of heat shock protein (AaeHsp26, AaeHsp83, and AaeHsc70) families are known to be expressed in mosquitoes, which aid in overcoming stress induced by elevated temperature. In this study, the relative expression of heat shock protein genes has been examined using Quantitative Real-time PCR (qPCR). The temperatures used for heat shock treatment were 27(control), 37, and 42°C for 1 hour heat shock period and applied to 3rd instar larvae. Significant up-regulation has been seen at 37, and 42°C. The highest expression level, about 82.43 fold, was reported for the AaeHsc70 gene at 42°C followed by 78.36 fold for AaeHsp26 at 37°C and 4.79 fold for AaeHsp83 at 42°C. The current study has shown that HSPs are important markers of stress and may function as critical proteins to protect and enhance the survival of Ae. aegypti larvae and pupae. Biological implications of these findings could impact the vector competencies Dhaka Univ. J. Biol. Sci. 30(2): 233-241, 2021 (July)

Dengue is a mosquito-borne viral disease caused by four serotypes of the dengue virus (DENV-1, DENV-2, DENV-3, and DENV-4), which has impacted human populations for decades in tropical and subtropical regions, including Bangladesh. Understanding the genetic variability and mutation patterns of DENV-2 and DENV-3 is critical for developing effective control strategies, as these serotypes are more prevalent in Bangladesh. The E/NS1 gene junction, which comprises less than 3% of the DENV genome, is a recognized hotspot for mutation. In this study, 56 E/NS1 junction sequences of DENV-2 from 36 countries, including Bangladesh, were analyzed in silico. The Bangladeshi sequences were compared with the DENV-2 prototype strain (New Guinea C) and sequences from other countries. Analysis of Bangladeshi DENV-2 isolates revealed only one amino acid substitution (isoleucine to valine at position 742, I742V), caused by a nucleotide change (ATT to GTC). Phylogenetic analysis placed all Bangladeshi DENV-2 isolates within the Cosmopolitan genotype. Similarly, 35 E/NS1 junction sequences of DENV-3 from 19 countries, including Bangladesh, were analyzed. Sequences from Bangladesh obtained in 2002 (eight isolates) and 2020 (two isolates) were compared with the DENV-3 prototype strain (Philippines H87). The 2020 isolates exhibited two common amino acid substitutions (A759V and V769A), while the 2002 isolates showed three substitutions (S727G, A759V, and V769T). Phylogenetic analysis revealed a genotypic shift in Bangladeshi DENV-3 isolates, with 2002 isolates belonging to Genotype II and 2020 isolates classified as Genotype I. Envelope protein modeling for both DENV-2 and DENV-3 Bangladeshi isolates, compared to their respective prototype strains, revealed no significant structural changes in the E protein. However, protein stability analysis, based on changes in free energy due to amino acid substitutions, indicated a potential impact on the stability of the mutant E proteins compared to the prototypes. Further studies are needed to explore the clinical implications of these mutations. Bioresearch Commu. 11(1): 1749-1763, 2025 (January)

Rapid emergence of covid-19 variants by continuous mutation made the world experience continuous waves of infections and as a result, a huge number of death-toll recorded so far. It is, therefore, very important to investigate the diversity and nature of the mutations in the SARS-CoV-2 genomes. In this study, the common mutations occurred in the whole genome sequences of SARS-CoV-2 variants of Bangladesh in a certain timeline were analyzed to better understand its status. Hence, a total of 78 complete genome sequences available in the NCBI database were obtained, aligned and further analyzed. Scattered Single Nucleotide Polymorphisms (SNPs) were identified throughout the genome of variants and common SNPs such as: 241:C>T in the 5′UTR of Open Reading Frame 1A (ORF1A), 3037: C>T in Non-structural Protein 3 (NSP3), 14,408: C>T in ORF6 and 23,402: A>G, 23,403: A>G in Spike Protein (S) were observed, but all of them were synonymous mutations. About 97% of the studied genomes showed a block of tri-nucleotide alteration (GGG>AAC), the most common non-synonymous mutation in the 28,881–28,883 location of the genome. This block results in two amino acid changes (203–204: RG>KR) in the SR rich motif of the nucleocapsid (N) protein of SARS-CoV-2, introducing a lysine in between serine and arginine. The N protein structure of the mutant was predicted through protein modeling. However, no observable difference was found between the mutant and the reference (Wuhan) protein. Further, the protein stability changes upon mutations were analyzed using the I-Mutant2.0 tool. The alteration of the arginine to lysine at the amino acid position 203, showed reduction of entropy, suggesting a possible impact on the overall stability of the N protein. The estimation of the non-synonymous to synonymous substitution ratio (dN/dS) were analyzed for the common mutations and the results showed that the overall mean distance among the N-protein variants were statistically significant, supporting the non-synonymous nature of the mutations. The phylogenetic analysis of the selected 78 genomes, compared with the most common genomic variants of this virus across the globe showed a distinct cluster for the analyzed Bangladeshi sequences. Further studies are warranted for conferring any plausible association of these mutations with the clinical manifestation.

Calorie restriction (CR) has been shown to increase longevity in various animals; however, the mechanisms by which it affects chromatin-modifying factors remain poorly understood. GCN5, a histone acetyltransferase, is a vital regulator of transcription that responds to metabolic and stress signals, linking nutrient signaling to chromatin remodeling, but the extent of its necessity in promoting longevity through caloric restriction (CR) has yet to be completely defined. We investigated chronological lifespan (CLS), growth dynamics, respiratory efficiency, oxidative stress tolerance, mitochondrial DNA (mtDNA) mutation rate, and mtDNA abundance in a yeast gcn5Δ mutant under both normal and glucose-restricted conditions in order to elucidate GCN5-independent effects of CR. Under CR, the mutant showed a significant increase in CLS along with a decreased growth rate and improved survival in the stationary phase. Despite the loss of GCN5, calorie restriction enhanced respiratory efficiency on non-fermentable substrates, improved survival under oxidative stress, increased mtDNA abundance, and reduced mtDNA mutations, suggesting improved mitochondrial integrity. Altogether, these results showed that CR can compensate for GCN5's absence by triggering alternative nutrient-sensing and mitochondrial maintenance systems. This information offers insights into chromatin-independent pathways that could be used to mitigate aging and mitochondrial dysfunction in higher organisms Bioresearch Commu. 12(1): 1961-1971, 2026 (January)