Genome-based classification of Calidifontibacillus erzurumensis gen. nov., sp. nov., isolated from a hot spring in Turkey, with reclassification of Bacillus azotoformans as Calidifontibacillus azotoformans comb. nov. and Bacillus oryziterrae as Calidifontibacillus oryziterrae comb. nov

From agro-food waste to nanoparticles: green synthesis of copper nanoparticles with lignin peroxidase enzyme produced by Anoxybacillus rupiensis using peanut shells

This study presents a novel approach for the eco-friendly green synthesis of copper nanoparticles (Cu NPs) using enzymatic mediation which is an environmentally benign alternative to conventional methods, offering control over particle size and shape. Anoxybacillus rupiensis BS1 thermophilic bacterium was isolated from Erzurum's Pasinler hot spring and lignin peroxidase enzyme production conditions (incubation time 96 h, 40 g/L shell amount, pH 8.5, 150 rpm, and 60 °C temperature) were used in the production of peroxidase enzyme using peanut waste which has been optimized. The characterization of the synthesized Cu NPs was performed using various analytical techniques, including UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), confirming the successful production of stable and well-defined nanoparticles. Furthermore, the biological activities of the synthesized Cu NPs were explored, revealing their potential for antimicrobial applications. The antibacterial efficacy of the Cu NPs against some pathogens such as Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, and Bacillus cereus was examined. It was determined that Cu NPs were effective on all pathogens and had the highest effectiveness against the S. pyogenes pathogen (19.0 mm). This study not only presents an innovative and sustainable approach for the synthesis of Cu NPs but also highlights the multifaceted biological activities of these nanoparticles, opening avenues for diverse applications in the fields of medicine, agriculture, and environmental remediation. The utilization of peanut shell wastes as a substrate for enzyme production adds value to agricultural by-products, contributing to the development of a circular and sustainable economy.

Isolation and identification of uric acid-dependent Aciduricibacillus chroicocephali gen. nov., sp. nov. from seagull feces and implications for hyperuricemia treatment

Hyperuricemia has become the second most prevalent metabolic disease after diabetes, but the limitations of urate-lowering treatment (ULT) drugs and patient nonadherence make ULT far less successful. Thus, more ULT approaches urgently need to be explored. Uric acid-degrading bacteria have potential application value in ULT. In this study, we isolated 44XBT, a uric acid-degrading bacterium, from black-headed gull (Chroicocephalus ridibundus) feces. Using a polyphasic taxonomic approach, strain 44XBT was identified as a novel genus within the family Bacillaceae; subsequently, the name Aciduricibacillus chroicocephali was proposed. Strain 44XBT had a unique uric acid-dependent phenotype and utilized uric acid and allantoin as the sole carbon and nitrogen sources, but not common carbon sources or complex media. In the genome, multiple copies of genes involved in uric acid metabolic pathway (pucL, pucM, uraD, and allB) were found. Six copies of pucL (encoding urate oxidase) were detected. Of these, five pucL copies were in a tandem arrangement and shared 70.42%-99.70% amino acid identity. In vivo experiments revealed that 44XBT reduced serum uric acid levels and attenuated kidney damage in hyperuricemic mice through uric acid catalysis in the gut and gut microbiota remodeling. In conclusion, our findings discover a strain for studying bacterial uric acid metabolism and may provide valuable insights into ULT.

IMPORTANCE

The increasing disease burden of hyperuricemia highlights the need for new therapeutic drugs and treatment strategies. Our study describes the developmental and application values of natural uric acid-degrading bacteria found in the gut of birds and broadened the source of bacteria with potential therapeutic value. Furthermore, the special physiology characteristics and genomic features of strain 44XBT are valuable for further study.

Bacillales: From Taxonomy to Biotechnological and Industrial Perspectives

For a long time, the genus Bacillus has been known and considered among the most applicable genera in several fields. Recent taxonomical developments resulted in the identification of more species in Bacillus-related genera, particularly in the order Bacillales (earlier heterotypic synonym: Caryophanales), with potential application for biotechnological and industrial purposes such as biofuels, bioactive agents, biopolymers, and enzymes. Therefore, a thorough understanding of the taxonomy, growth requirements and physiology, genomics, and metabolic pathways in the highly diverse bacterial order, Bacillales, will facilitate a more robust designing and sustainable production of strain lines relevant to a circular economy. This paper is focused principally on less-known genera and their potential in the order Bacillales for promising applications in the industry and addresses the taxonomical complexities of this order. Moreover, it emphasizes the biotechnological usage of some engineered strains of the order Bacillales. The elucidation of novel taxa, their metabolic pathways, and growth conditions would make it possible to drive industrial processes toward an upgraded functionality based on the microbial nature.

Purification and biochemical characterization of a new thermostable laccase from Enterococcus faecium A2 by a three-phase partitioning method and investigation of its decolorization potential

Three-phase partitioning (TPP) is a simple, fast, cost-effective, and highly efficient process that can be used in the purification of laccases. In this study, microorganisms with laccase activity were isolated from water samples collected from the Agri-Diyadin hot spring. The isolate with the highest laccase activity was found to be the A2 strain. As a result of molecular (16S rRNA sequence) and conventional (morphological, biochemical, and physiological) analyses, it was determined that the A2 isolate was 99% similar to Enterococcus faecium (Genbank number: MH424896). The laccase was purified to 4.9-fold with 110% recovery using the TPP. The molecular mass of the enzyme was found by SDS-PAGE to be 50.11 kDa. Optimum pH 6.0 and optimum temperature for laccase were determined as 80 °C. The laccase exhibited pH stability over a wide range (pH 3.0-9.0) and a high thermostability, retaining over 90% of its activity after 1 h of incubation at 20-90 °C. The laccase exhibited high thermostability, with a heat inactivation half-life of approximately 24 h at 80 °C. The enzyme remained highly stable in the presence of surfactants and increased its activity in the presence of organic solvents, Cr²⁺, Cu²⁺, and Ag⁺ metal ions. The K_m, V_max, k_cat, and k_cat/K_m values of laccase for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) substrate were 0.68 mM, 5.29 μmol mL^-1 min^-1, 110.2 s^-1, and 162.1 s^-1 mM^-1, respectively.