With the exponential spread of the coronavirus disease 2019 (COVID‐19) pandemic across the world within the 12 months, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) strains are continuously trying to adapt themselves to the host environment by random mutations. When doing so, some variants with evolutionary advantages such as better human to human transmissibility potential might get naturally selected. This short communication demonstrates how the mutation frequency patterns are evolving in 2457 SAR‐CoV‐2 strains isolated from COVID‐19 patients across diverse Indian states. We have identified 19 such variants showing contrasting mutational probabilities in the span of 7 months. Out of these, 14 variants are showing increasing mutational probabilities suggesting their propagation with time due to their unexplored evolutionary advantages. However, the mutational probabilities of five variants have significantly decreased in June onward as compared to March/April, suggesting their termination with time. Further in‐depth investigation of these identified variants will provide valuable knowledge about the evolution, infection strategies, transmission rates, and epidemiology of SARS‐CoV‐2.

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The nitrogen‐fixing, non‐heterocystous cyanobacterium Hydrocoleum sp. (Oscillatoriales) is a common epiphytic and benthic bloom‐former in tropical and subtropical shallow water systems but shares high phylogenetic similarity with the planktonic, globally important diazotroph Trichodesmium. Multiphasic observations in this study resulted in unexpected identification of Hydrocoleum sp. in mass accumulations in a coastal lagoon in the Western temperate North Atlantic Ocean. Hydrocoleum physiology was examined in situ through measurements of N2 and CO2 fixation rates and expression of genes involved with N2 fixation, CO2 fixation, and phosphorus (P) stress. Bulk N2 fixation rates and Hydrocoleum nifH expression peaked at night and were strongly suppressed by dissolved inorganic nitrogen (DIN). The expression of high affinity phosphate transporter (pstS) and alkaline phosphatase (phoA) genes of Hydrocoleum was elevated during the night and negatively responded to phosphate amendments, as evidence that these mechanisms contribute to P acquisition during diazotrophic growth of Hydrocoleum in situ. This discovery at the edge of the previously known Hydrocoleum habitat range in the warming oceans raises intriguing questions about diazotrophic cyanobacterial adaptations and transitions on the benthic‐pelagic continuum.

With the exponential spread of COVID-19 pandemic across the world within the last six months, SARS-CoV-2 strains are continuously trying to adapt themselves in their host environment by random mutations. While doing so, some variants with evolutionary advantages such as better human to human transmissibility potential should get naturally selected. This short communication demonstrates how the mutation probability patterns are evolving in 864 SAR-CoV-2 strains isolated from COVID-19 patients across diverse Indian states. We have identified 30 such variants showing contrasting mutational probabilities in the span of four months. Out of these, the mutational probabilities of 25 variants including C14408T (in RdRp gene), A23403G (in spike gene), C6312A (nsp3 gene) are continuously increasing suggesting that these mutations are being propagated with time due to their unexplored evolutionary advantages. In contrast, the mutational probabilities of five variants including C6312A (nsp3 gene), G11083T (nsp6 gene), C28311T (N gene) have significantly decreased in May-June as compared to March-April, suggesting these mutations are being terminated with time. Further in-depth investigation of these identified variants will provide valuable knowledge about the evolution, infection strategies, transmission rates, and epidemiology of SARS-CoV-2 in India.

Clustered regularly interspaced short palindromic repeats (CRISPRs) are known to provide adaptive immunity to bacteria against invading bacteriophages. In recent years, CRISPR-based technologies have been used for creating improved plant varieties; however, the indigenous CRISPR–Cas elements of plant growth-promoting bacteria are usually neglected. These indigenous genetic cassettes have evolved over millions of years and have shaped the bacterial genome. Therefore, these genetic loci can be used to study the adaptive capability of the bacteria in the environment. This study aims to bioinformatically analyze the genomes of a common free-living nitrogen-fixing Azotobacter spp. to assess their CRISPR–Cas diversity. Strains of Azotobacter vinelandii and Azotobacter chroococcum were found to harbor a large number of spacers. The phylogeny of different Cas and Cse1 proteins revealed a close evolutionary relationship among A. chroococcum B3, A. chroococcum NCIMB 8003 locus II, and A. vinelandii DJ locus I. The secondary structure of the hairpin loop of the repeat was also analyzed, and a correlation was derived between the structural stability of the hairpin loop and the number of spacers acquired by the CRISPR loci. These findings revealed the diversity and evolution of the CRISPR sequences and Cas proteins in Azotobacter species. Although the adaptive immune system of bacteria against bacteriophage, CRISPR–Cas, has been identified in many bacteria, studies of plant growth-promoting bacteria have been neglected. These indigenous CRISPRs have shaped the genome over millions of years and their study can lead to the understanding of the genome composition of these organisms. Our results strengthen the idea of using A. chroococcum and A. vinelandii as biofertilizer strains as they possess more spacers with highly stable repeat sequences, thereby imparting them higher chance of survival against mobile genetic elements like phages and plasmids.