Srivastava Arpit, Rai Piyush Kant, Agnihotri Vivek Kumar, Choure Kamlesh, Vishvakarma Reena
Department of Bioengineering, Integral University, Lucknow, Uttar Pradesh, 226026, India.
Department of Biotechnology, AKS University, Satna, Madhya Pradesh, 485001, India.
Int Microbiol. 2025 Jun 4. doi: 10.1007/s10123-025-00677-0.
Varuna River, which is native to Varanasi, is of great importance as a water reservoir for the people and is contaminated with heavy pollutants due to urbanization. In this study, four sites (VR1, VR2, VR3, and VR4) of Varuna River water were sampled to assess the viral diversity. The metagenomics approach was used to study the viral diversity and functional analysis, suggesting the overall quality of the water at the sampled location. The analysis shows that VR1 had the most species richness (3000 species), followed by VR3 (2500), VR2 (2000), and VR4 (1500). The PCA analysis revealed distinct spatial patterns and community differentiation where VR2 and VR4 clustered while VR1 and VR3 were distant.Diversity analysis showed that Negarnaviricota dominated all samples at the phylum level. Yunchangviricetes, a non-reported virus, and Insthoviricetes were the dominant classes. Pakpunavirus was the leading genus, followed by the human pathogen Mimivirus. The highest species abundance in VR1 and VR2 was Mimivirus, Megavirus, chilensis, while VR3 and VR4 had Hpunavirus and Pseudomonas phage O4, indicating human involvement. Functional analyses of enzymatic activity and KEGG Orthology in microbial communities from VR1 to VR4 samples showed that VR4 exhibited maximal enzymatic activity, genetic flexibility, and advanced regulatory control compared to the other samples. The increased presence of transporter genes alongside signal transduction proteins and metabolic enzymes in VR4 indicates enhanced functional diversity, which aids in coping with environmental stresses. On the basis of viral species, ecological, biotechnological aspects were also interpreted. This study concluded that the Negarnaviricota plays a key role in maintaining the overall water quality and there is an urgent need for remediation of the Varuna River especially at site VR4 (25° 19' 46.7″ N 83° 02' 38.3″ E).
瓦鲁纳河发源于瓦拉纳西，对当地居民而言是极为重要的水源地，但由于城市化进程，该河流受到了严重的污染物污染。在本研究中，采集了瓦鲁纳河四个位点（VR1、VR2、VR3和VR4）的水样，以评估病毒多样性。采用宏基因组学方法研究病毒多样性并进行功能分析，以此推断采样位点处水的整体质量。分析表明，VR1的物种丰富度最高（3000种），其次是VR3（2500种）、VR2（2000种）和VR4（1500种）。主成分分析揭示了不同的空间格局和群落分化，其中VR2和VR4聚类在一起，而VR1和VR3相距较远。多样性分析表明，在门水平上，Negarnaviricota在所有样本中占主导地位。未报道过的病毒Yunchangviricetes和Insthoviricetes是主要的纲。Pakpunavirus是主要的属，其次是人类病原体米米病毒。VR1和VR2中物种丰度最高的是米米病毒、巨病毒、智利病毒，而VR3和VR4中则是Hpunavirus和假单胞菌噬菌体O4，这表明受到了人类活动的影响。对VR1至VR4样本中微生物群落的酶活性和KEGG直系同源物进行功能分析表明，与其他样本相比，VR4表现出最大的酶活性、遗传灵活性和先进的调控控制。VR4中转运蛋白基因与信号转导蛋白和代谢酶的增加表明其功能多样性增强，这有助于应对环境压力。基于病毒种类，还对生态和生物技术方面进行了解释。本研究得出结论，Negarnaviricota在维持整体水质方面起着关键作用，迫切需要对瓦鲁纳河进行修复，尤其是在VR4位点（北纬25°19'46.7″，东经83°02'38.3″）。
