Insights into freshwater ciliate diversity through high throughput DNA metabarcoding.

The freshwater bodies of India are highly biodiverse but still understudied, especially concerning ciliates. Ciliates constitute a significant portion of eukaryotic diversity and play crucial roles in microbial loops, nutrient recycling, and ecosystem maintenance. The present study aimed to elucidate ciliate diversity in three freshwater sites in the Delhi region of India: Okhla Bird Sanctuary (OBS), Sanjay Lake (SL), and Raj Ghat pond (RJ). This study represents the first investigation into the taxonomic diversity and richness of freshwater ciliates in India using a high-throughput DNA metabarcoding approach. For the analysis, total environmental DNA was extracted from the three freshwater samples, followed by sequencing of the 18S V4 barcode region and subsequent phylogenetic analyses. Operational taxonomic units (OTU) analyses revealed maximum species diversity in OBS (106), followed by SL (104) and RJ (99) sites. Ciliates from the classes Oligohymenophorea, Prostomatea, and Spirotrichea were dominant in the three sites. The study discusses the ability of the metabarcoding approach to uncover unknown and rare species. The study highlights the need for refined reference databases and cautious interpretation of the high-throughput sequencing-generated data while emphasizing the complementary nature of molecular and morphological approaches in studying ciliate diversity.

Amycolatopsis mediterranei: A Sixty-Year Journey from Strain Isolation to Unlocking Its Potential of Rifamycin Analogue Production by Combinatorial Biosynthesis.

Ever since the isolation of Amycolatopsis mediterranei in 1957, this strain has been the focus of research worldwide. In the last 60 years or more, our understanding of the taxonomy, development of cloning vectors and conjugation system, physiology, genetics, genomics, and biosynthetic pathway of rifamycin B production in A. mediterranei has substantially increased. In particular, the development of cloning vectors, transformation system, characterization of the rifamycin biosynthetic gene cluster, and the regulation of rifamycin B production by the pioneering work of Heinz Floss have made the rifamycin polyketide biosynthetic gene cluster (PKS) an attractive target for extensive genetic manipulations to produce rifamycin B analogues which could be effective against multi-drug-resistant tuberculosis. Additionally, a better understanding of the regulation of rifamycin B production and the application of newer genomics tools, including CRISPR-assisted genome editing systems, might prove useful to overcome the limitations associated with low production of rifamycin analogues.

Phylogenomics-based reclassifications in the genus Psychrobacter including emended descriptions of Psychrobacter pacificensis, Psychrobacter proteolyticus and Psychrobacter submarinus.

The taxonomic status of 43 Psychrobacter species was examined based upon the genome sequences of their type strains. Three groups of type strains were found to be conspecific, Psychrobacter salsus Shivaji et al. (Syst Appl Microbiol 27:628-635, 2004. 10.1078/0723202042369956) and Psychrobacter submarinus Romanenko et al. (Int J Syst Evol Microbiol 52:1291-1297, 2002. 10.1099/00207713-52-4-1291); Psychrobacter oceani Matsuyama et al. (Int J Syst Evol Microbiol 65:1450-1455, 2015. 10.1099/ijs.0.000118) and Psychrobacter pacificensis Maruyama et al. (Int J Syst Evol Microbiol 50:835-846, 2000. 10.1099/00207713-50-2-835); and Psychrobacter proteolyticus Denner et al. (Syst Appl Microbiol 24:44-53, 2001. 10.1078/0723-2020-00006), Psychrobacter marincola Romanenko et al. (Int J Syst Evol Microbiol 52:1291-1297, 2002. 10.1099/00207713-52-4-1291) and Psychrobacter adeliensis Shivaji et al. (Syst Appl Microbiol 27:628-635, 2004. 10.1078/0723202042369956). For all three groups, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values are > 97.69% and > 80.2%, respectively. This conclusion is supported by similarities in morphology, growth properties, and fatty acid compositions. Based on this evidence, we propose the reclassification of Psychrobacter salsus Shivaji et al. (Syst Appl Microbiol 27:628-635, 2004. 10.1078/0723202042369956) as a later heterotypic synonym of Psychrobacter submarinus Romanenko et al. (Int J Syst Evol Microbiol 52:1291-1297, 2002. 10.1099/00207713-52-4-1291); Psychrobacter oceani Matsuyama et al. (Int J Syst Evol Microbiol 65:1450-1455, 2015. 10.1099/ijs.0.000118) as a later heterotypic synonym of Psychrobacter pacificensis Maruyama et al. (Int J Syst Evol Microbiol 50:835-846, 2000. 10.1099/00207713-50-2-835), and Psychrobacter marincola Romanenko et al. (Int J Syst Evol Microbiol 52:1291-1297, 2002. 10.1099/00207713-52-4-1291) and Psychrobacter adeliensis Shivaji et al. (Syst Appl Microbiol 27:628-635, 2004. 10.1078/0723202042369956) as later heterotypic synonyms of Psychrobacter proteolyticus Denner et al. (Syst Appl Microbiol 24:44-53, 2001. 10.1078/0723-2020-00006).

Cyanobacterial compound Tolyporphine K as an inhibitor of Apo-PBP (penicillin-binding protein) in A. baumannii and its ADME assessment.

Antibiotic-resistant Acinetobacter baumannii, is a common pathogen found in hospital settings and has become nosocomial due to its high infection-causing tendency amongst ICU patients. The present study explores the cyanocompoundswhich were capable to inhibit the Penicillin Binding Protein of A. baumannii through molecular docking, ADMET, and molecular dynamicssimulation strategy. A database having structural and origin details was generated for 85 bioactive compounds in MS Excel. The 3-D structures weredownloaded from the PubChem database and minimized. The receptor protein was minimized and validated for structure correctness. The database was screened against the penicillin-binding protein of A. baumannii through PyRx software. The top 5 compounds including the control molecule werefurther redocked to the receptor molecule through Autodock Vina software. The molecule pose having the highest affinity was further subjected to 100ns MD- simulation and simultaneously the in-vitro activity of the methanol extract and hexane extract was checked through agar well diffusion assay.Docking studies indicate Tolyporphine K to be a lead molecule which was further assessed through Molecular dynamics and MM/PBSA. The in-silicoresults suggested that the protein-ligand complex was found to be stable over the 100 ns trajectory with a binding free energy of -8.56 Kcalmol-1. Theligand did not induce any major structural conformation in the protein moiety and was largely stabilized by hydrophobic interactions. The bioactivityscore and ADME properties of the compounds were also calculated. The in-vitro agar well diffusion assay showed a moderate zone of inhibition of12.33mm. The results indicate that the compound Tolyporphin- K could be a potential inhibitor of penicillin-binding protein in A. baumannii. Yet furtherwork needs to be done to have a more concrete basis for the pathway of inhibition.Communicated by Ramaswamy H. Sarma.

Monkeypox virus: phylogenomics, host-pathogen interactome and mutational cascade.

While the world is still recovering from the Covid-19 pandemic, monkeypox virus (MPXV) awaits to cause another global outbreak as a challenge to all of mankind. However, the Covid-19 pandemic has taught us a lesson to speed up the pace of viral genomic research for the implementation of preventive and treatment strategies. One of the important aspects of MPXV that needs immediate insight is its evolutionary lineage based on genomic studies. Utilizing high-quality isolates from the GISAID (Global Initiative on Sharing All Influenza Data) database, primarily sourced from Europe and North America, we employed a SNP-based whole-genome phylogeny method and identified four major clusters among 628 MPXV isolates. Our findings indicate a distinct evolutionary lineage for the first MPXV isolate, and a complex epidemiology and evolution of MPXV strains across various countries. Further analysis of the host-pathogen interaction network revealed key viral proteins, such as E3, SPI-2, K7 and CrmB, that play a significant role in regulating the network and inhibiting the host's cellular innate immune system. Our structural analysis of proteins E3 and CrmB revealed potential disruption of stability due to certain mutations. While this study identified a large number of mutations within the new outbreak clade, it also reflected that we need to move fast with the genomic analysis of newly detected strains from around the world to develop better prevention and treatment methods.

Weaponising microbes for peace.

There is much human disadvantage and unmet need in the world, including deficits in basic resources and services considered to be human rights, such as drinking water, sanitation and hygiene, healthy nutrition, access to basic healthcare, and a clean environment. Furthermore, there are substantive asymmetries in the distribution of key resources among peoples. These deficits and asymmetries can lead to local and regional crises among peoples competing for limited resources, which, in turn, can become sources of discontent and conflict. Such conflicts have the potential to escalate into regional wars and even lead to global instability. Ergo: in addition to moral and ethical imperatives to level up, to ensure that all peoples have basic resources and services essential for healthy living and to reduce inequalities, all nations have a self-interest to pursue with determination all available avenues to promote peace through reducing sources of conflicts in the world. Microorganisms and pertinent microbial technologies have unique and exceptional abilities to provide, or contribute to the provision of, basic resources and services that are lacking in many parts of the world, and thereby address key deficits that might constitute sources of conflict. However, the deployment of such technologies to this end is seriously underexploited. Here, we highlight some of the key available and emerging technologies that demand greater consideration and exploitation in endeavours to eliminate unnecessary deprivations, enable healthy lives of all and remove preventable grounds for competition over limited resources that can escalate into conflicts in the world. We exhort central actors: microbiologists, funding agencies and philanthropic organisations, politicians worldwide and international governmental and non-governmental organisations, to engage - in full partnership - with all relevant stakeholders, to 'weaponise' microbes and microbial technologies to fight resource deficits and asymmetries, in particular among the most vulnerable populations, and thereby create humanitarian conditions more conducive to harmony and peace.

DNA barcoding, an effective tool for species identification: a review.

DNA barcoding is a powerful taxonomic tool to identify and discover species. DNA barcoding utilizes one or more standardized short DNA regions for taxon identification. With the emergence of new sequencing techniques, such as Next-generation sequencing (NGS), ONT MinION nanopore sequencing, and Pac Bio sequencing, DNA barcoding has become more accurate, fast, and reliable. Rapid species identification by DNA barcodes has been used in a variety of fields, including forensic science, control of the food supply chain, and disease understanding. The Consortium for Barcode of Life (CBOL) presents various working groups to identify the universal barcode gene, such as COI in metazoans; rbcL, matK, and ITS in plants; ITS in fungi; 16S rRNA gene in bacteria and archaea, and creating a reference DNA barcode library. In this article, an attempt has been made to analyze the various proposed DNA barcode for different organisms, strengths & limitations, recent advancements in DNA barcoding, and methods to speed up the DNA barcode reference library construction. This study concludes that constructing a reference library with high species coverage would be a major step toward identifying species by DNA barcodes. This can be achieved in a short period of time by using advanced sequencing and data analysis methods.

Phylogenetic Analyses of Microbial Hydrolytic Dehalogenases Reveal Polyphyletic Origin.

Hydrolytic dehalogenases form an important class of dehalogenases that include haloacid dehalogenase, haloalkane dehalogenase, haloacetate dehalogenase, and atrazine chlorohydrolase. These enzymes are involved in biodegradation of various environmental pollutants and therefore it is important to understand their phylogeny. In the present study, it was found that the enzymes haloalkane and haloacetate dehalogenases share a common ancestry with enzymes such as carboxyesterase, epoxide hydrolase, and lipases, which can be traced to ancestral α/ß hydrolase fold enzyme. Haloacid dehalogenases and atrazine chlorohydrolases have probabaly evolved from ancestral enzymes with phosphatase and deaminases activity, respectively. These findings were supported by the similarities in the secondary structure, key catalytic motifs and placement of catalytic residues. The phylogeny of haloalkane dehalogenases and haloacid dehalogenases differs from 16S rRNA gene phylogeny, suggesting spread through horizontal gene transfer. Hydrolytic dehalogenases are polyphyletic and do not share a common evolutionay history, the functional similarities are due to convergent evolution. The present study also identifies key functional residues, mutating which, can help in generating better enzymes for clean up of the persistent environmental pollutants using enzymatic bioremediation. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01043-8.

Microbial Journey: Mount Everest to Mars.

A rigorous exploration of microbial diversity has revealed its presence on Earth, deep oceans, and vast space. The presence of microbial life in diverse environmental conditions, ranging from moderate to extreme temperature, pH, salinity, oxygen, radiations, and altitudes, has provided the necessary impetus to search for them by extending the limits of their habitats. Microbiology started as a distinct science in the mid-nineteenth century and has provided inputs for the betterment of mankind during the last 150 years. As beneficial microbes are assets and pathogens are detrimental, studying both have its own merits. Scientists are nowadays working on illustrating the microbial dynamics in Earth's subsurface, deep sea, and polar regions. In addition to studying the role of microbes in the environment, the microbe-host interactions in humans, animals and plants are also unearthing newer insights that can help us to improve the health of the host by modulating the microbiota. Microbes have the potential to remediate persistent organic pollutants. Antimicrobial resistance which is a serious concern can also be tackled only after monitoring the spread of resistant microbes using disciplines of genomics and metagenomics The cognizance of microbiology has reached the top of the world. Space Missions are now looking for signs of life on the planets (specifically Mars), the Moon and beyond them. Among the most potent pieces of evidence to support the existence of life is to look for microbial, plant, and animal fossils. There is also an urgent need to deliberate and communicate these findings to layman and policymakers that would help them to take an adequate decision for better health and the environment around us. Here, we present a glimpse of recent advancements by scientists from around the world, exploring and exploiting microbial diversity.

Evaluation of TiO2 Nanoparticles Physicochemical Parameters Associated with their Antimicrobial Applications.

Titanium dioxide nanoparticles (TiO2NPs) usage is increasing in everyday consumer products, hence, assessing their toxic impacts on living organisms and environment is essential. Various studies have revealed the significant role of TiO2NPs physicochemical properties on their toxicity. However, TiO2NPs are still poorly characterized with respect to their physicochemical properties, and environmental factors influencing their toxicity are either ignored or are too complex to be assessed under laboratory conditions. The outcomes of these studies are diverse and inconsistent due to lack of standard protocols. TiO2NPs toxicity also differs for in vivo and in vitro systems, which must also be considered during standardization of protocols to maintain uniformity and reproducibility of results. This review critically evaluates impact of different physicochemical parameters of TiO2NPs and other experimental conditions, employed in different laboratories in determining their toxicity towards bacteria. These important observations may be helpful in evaluation of environmental risks posed by these nanoparticles and this can further assist regulatory bodies in policymaking.

Microbial Ecology of Sulfur Biogeochemical Cycling at a Mesothermal Hot Spring Atop Northern Himalayas, India.

Sulfur related prokaryotes residing in hot spring present good opportunity for exploring the limitless possibilities of integral ecosystem processes. Metagenomic analysis further expands the phylogenetic breadth of these extraordinary sulfur (S) metabolizing microorganisms as well as their complex metabolic networks and syntrophic interactions in environmental biosystems. Through this study, we explored and expanded the microbial genetic repertoire with focus on S cycling genes through metagenomic analysis of S contaminated hot spring, located at the Northern Himalayas. The analysis revealed rich diversity of microbial consortia with established roles in S cycling such as Pseudomonas, Thioalkalivibrio, Desulfovibrio, and Desulfobulbaceae (Proteobacteria). The major gene families inferred to be abundant across microbial mat, sediment, and water were assigned to Proteobacteria as reflected from the reads per kilobase (RPKs) categorized into translation and ribosomal structure and biogenesis. An analysis of sequence similarity showed conserved pattern of both dsrAB genes (n = 178) retrieved from all metagenomes while other S disproportionation proteins were diverged due to different structural and chemical substrates. The diversity of S oxidizing bacteria (SOB) and sulfate reducing bacteria (SRB) with conserved (r)dsrAB suggests for it to be an important adaptation for microbial fitness at this site. Here, (i) the oxidative and reductive dsr evolutionary time-scale phylogeny proved that the earliest (but not the first) dsrAB proteins belong to anaerobic Thiobacillus with other (rdsr) oxidizers, also we confirm that (ii) SRBs belongs to δ-Proteobacteria occurring independent lateral gene transfer (LGT) of dsr genes to different and few novel lineages. Further, the structural prediction of unassigned DsrAB proteins confirmed their relatedness with species of Desulfovibrio (TM score = 0.86, 0.98, 0.96) and Archaeoglobus fulgidus (TM score = 0.97, 0.98). We proposed that the genetic repertoire might provide the basis of studying time-scale evolution and horizontal gene transfer of these genes in biogeochemical S cycling.

Filamentous Thermosensitive Mutant Z: An Appealing Target for Emerging Pathogens and a Trek on Its Natural Inhibitors.

Antibiotic resistance is a major emerging issue in the health care sector, as highlighted by the WHO. Filamentous Thermosensitive mutant Z (Fts-Z) is gaining significant attention in the scientific community as a potential anti-bacterial target for fighting antibiotic resistance among several pathogenic bacteria. The Fts-Z plays a key role in bacterial cell division by allowing Z ring formation. Several in vitro and in silico experiments have demonstrated that inhibition of Fts-Z can lead to filamentous growth of the cells, and finally, cell death occurs. Many natural compounds that have successfully inhibited Fts-Z are also studied. This review article intended to highlight the structural-functional aspect of Fts-Z that leads to Z-ring formation and its contribution to the biochemistry and physiology of cells. The current trend of natural inhibitors of Fts-Z protein is also covered.

Pedobacter fastidiosus sp. nov., isolated from glacial habitats of maritime Antarctica.

Strains P8930T and 478 were isolated from Antarctic glaciers located on James Ross Island and King George Island, respectively. They comprised Gram-stain-negative short rod-shaped cells forming pink pigmented colonies and exhibited identical 16S rRNA gene sequences and highly similar MALDI TOF mass spectra, and hence were assigned as representatives of the same species. Phylogenetic analysis based on 16S rRNA gene sequences assigned both isolates to the genus Pedobacter and showed Pedobacter frigidisoli and Pedobacter terrae to be their closest phylogenetic neighbours, with 97.4 and 97.2 % 16S rRNA gene sequence similarities, respectively. These low similarity values were below the threshold similarity value of 98.7%, confirming the delineation of a new bacterial species. Further genomic characterization included whole-genome sequencing accompanied by average nucleotide identity (ANI) and digital DNA-DNA hybridization calculations, and characterization of the genome features. The ANI values between P8930T and P. frigidisoli RP-3-11T and P. terrae DSM 17933T were 79.7 and 77.6 %, respectively, and the value between P. frigidisoli RP-3-11T and P. terrae DSM 17933T was 77.7 %, clearly demonstrating the phylogenetic distance and the novelty of strain P8930T. Further characterization included analysis of cellular fatty acids, quinones and polar lipids, and comprehensive biotyping. All the obtained results proved the separation of strains P8930T and 478 from the other validly named Pedobacter species, and confirmed that they represent a new species for which the name Pedobacter fastidiosus sp. nov. is proposed. The type strain is P8930T (=CCM 8938T=LMG 32098T).

Harnessing taxonomically diverse and metabolically versatile genus Paracoccus for bioplastic synthesis and xenobiotic biodegradation.

The genus Paracoccus represents a taxonomically diverse group comprising more than 80 novel species isolated from various pristine and polluted environments. The species are characterized as coccoid-shaped Gram-negative bacteria with versatile metabolic attributes and classified as autotrophs, heterotrophs and/or methylotrophs. The present study highlights the up-to-date global taxonomic diversity and critically discusses the significance of genome analysis for identifying the genomic determinants related to functional attributes mainly bioplastic synthesis and biodegradation potential that makes these isolates commercially viable. The analysis accentuates polyphasic and genomic attributes of Paracoccus spp. which could be harnessed for commercial applications and emphasizes the need of integrating genome-based computational analysis for evolutionary species and functional diversification. The work reflects on the underexplored genetic potential for bioplastic synthesis which can be harnessed using advanced genomic methods. It also underlines the degradation potential and possible use of naturally-occurring pollutant-degrading Paracoccus isolates for the development of a biodegradation system and efficient removal of contaminants. The work contemplates plausible use of such potent isolates to establish the plant-microbe interaction, contributing toward contaminated land reclamation. Overall, the work signifies the need and application of genome analysis to identify and explore the prospective potential of Paracoccus spp. for environmental application toward achieving sustainability.

Inhibition of Filamentous Thermosensitive Mutant-Z Protein in Bacillus subtilis by Cyanobacterial Bioactive Compounds.

Antibiotic resistance is one of the major growing concerns for public health. Conventional antibiotics act on a few predefined targets and, with time, several bacteria have developed resistance against a large number of antibiotics. The WHO has suggested that antibiotic resistance is at a crisis stage and identification of new antibiotics and targets could be the only approach to bridge the gap. Filamentous Temperature Sensitive-Mutant Z (Fts-Z) is one of the promising and less explored antibiotic targets. It is a highly conserved protein and plays a key role in bacterial cell division by introducing a cytokinetic Z-ring formation. In the present article, the potential of over 165 cyanobacterial compounds with reported antibiotic activity against the catalytic core domain in the Fts-Z protein of the Bacillus subtilis was studied. The identified cyanobacterial compounds were screened using the GLIDE module of Maestro v-2019-2 followed by 100-ns molecular dynamics (MD) simulation. Ranking of the potential compound was performed using dock score and MMGBSA based free energy. The study reported that the docking score of aphanorphine (-6.010 Kcalmol-1) and alpha-dimorphecolic acid (ADMA) (-6.574 Kcalmol-1) showed significant role with respect to the reported potential inhibitor PC190723 (-4.135 Kcalmol-1). A 100 ns MD simulation infers that Fts-Z ADMA complex has a stable conformation throughout the progress of the simulation. Both the compounds, i.e., ADMA and Aphanorphine, were further considered for In-vitro validation by performing anti-bacterial studies against B. subtilis by agar well diffusion method. The results obtained through In-vitro studies confirm that ADMA, a small molecule of cyanobacterial origin, is a potential compound with an antibacterial activity that may act by inhibiting the novel target Fts-Z and could be a great drug candidate for antibiotic development.

The rising dominance of microbiology: what to expect in the next 15 years?

What microbiology beholds after a decade and a half in the future requires a vision based on the facts and ongoing trends in research and technological advancements. While the latter, assisted by microbial dark matter, presents a greater potential of creating an upsurge in in-situ and ex-situ rapid microbial detection techniques, this anticipated change will also set forth a revolution in microbial cultivation and diversity analyses. The availability of a microbial genetic toolbox at the expanse will help complement the current understanding of the microbiome and assist in real-time monitoring of the dynamics for detecting the health status of the host with utmost precision. Alongside, in light of the emerging infectious diseases, antimicrobial resistance (AMR) and social demands for safer and better health care alternatives, microbiology laboratories are prospected to drift in terms of the volume and nature of research and outcomes. With today's microbiological lens, one can predict with certainty that in the years to come, microbes will play a significant role in therapeutic treatment and the designing of novel diagnostic techniques. Another area where the scope of microbial application seems to be promising is the use of novel probiotics as a method to offer health benefits whilst promoting metabolic outputs specific for microbiome replenishment. Nonetheless, the evolution of extraterrestrial microbes or the adaptation of earth microbes as extraterrestrial residents are also yet another prominent microbial event one may witness in the upcoming years. But like the two sides of the coin, there is also an urgent need to dampen the bloom of urbanization, overpopulation and global trade and adopting sustainable approaches to control the recurrence of epidemics and pandemics.