Isoptericola haloaureus sp. nov., a dimorphic actinobacterium isolated from mangrove sediments of southeast India, implicating biosaline agricultural significance through nitrogen fixation and salt tolerance genes.

Strain MP-1014T, an obligate halophilic actinobacterium, was isolated from the mangrove soil of Thandavarayancholanganpettai, Tamil Nadu, India. A polyphasic approach was utilized to explore its phylogenetic position completely. The isolate was Gram-positive, filamentous, non-motile, and coccoid in older cultures. Ideal growth conditions were seen at 30 °C and pH 7.0, with 5% NaCl (W/V), and the DNA G + C content was 73.3%. The phylogenic analysis of this strain based upon 16S rRNA gene sequence revealed 97-99.8% similarity to the recognized species of the genus Isoptericola. Strain MP-1014T exhibits the highest similarity to I. sediminis JC619T (99.7%), I. chiayiensis KCTC19740T (98.9%), and subsequently to I. halotolerans KCTC19646T (98.6%), when compared with other members within the Isoptericola genus (< 98%). ANI scores of strain MP-1014T are 86.4%, 84.2%, and 81.5% and dDDH values are 59.7%, 53.6%, and 34.8% with I. sediminis JC619T, I. chiayiensis KCTC19740T and I. halotolerans KCTC19646T respectively. The major polar lipids of the strain MP-1014T were phosphatidylinositol, phosphatidylglycerol, diphosphotidylglycerol, two unknown phospholipids, and glycolipids. The predominant respiratory menaquinones were MK9 (H4) and MK9 (H2). The major fatty acids were anteiso-C15:0, anteiso-C17:0, iso-C14:0, C15:0, and C16:0. Also, initial genome analysis of the organism suggests it as a biostimulant for enhancing agriculture in saline environments. Based on phenotypic and genetic distinctiveness, the strain MP-1014 T represents the novel species of the genus Isoptericola assigned Isoptericola haloaureus sp. nov., is addressed by the strain MP-1014 T, given its phenotypic, phylogenetic, and hereditary uniqueness. The type strain is MP-1014T [(NCBI = OP672482.1 = GCA_036689775.1) ATCC = BAA 2646T; DSMZ = 29325T; MTCC = 13246T].

Plant biomass extracted eco-friendly natural surfactant enhanced bio-electrokinetic remediation of crude oil contaminated soil.

The current work investigates bioremediation (BIO) and electrokinetic (EK) remediation of crude oil hydrocarbons utilizing the biomass-electrokinetic (BIO-EK) approaches. The use of natural surfactants derived from plant biomass may improve remediation capacity by enhancing the solubility of organic pollutants. Sapindus mukorossi, a natural surfactant producer, was extracted from plant biomass in this study. The crude oil biodegradation efficiency was reported to be 98 %. In nature, FTIR confirms that plant biomass is lipopeptide. GCMS revealed that the crude oil (C7 - C23) was efficiently bio-degraded from lower to higher molecular weight. The application of natural surfactants in electokinetic remediation increased the plant biomass degradation of crude oil polluted soil by 98% compared to electrokinetic 55% in 2 days. Natural surfactant improves hydrocarbon solubilization and accelerates hydrocarbon electro migration to the anodic compartment, as confirmed by the presence of greater total organic content than the electrokinetic. This study proves that BIO-EK compared with a natural surfactant derived from plant biomass may be utilized to improve in situ bioremediation of crude oil polluted soils.

The osmoprotective effect of some organic solutes on Streptomyces sp. mado2 and nocardiopsis sp. mado3 growth

The response of two marine actinomycetes such as Streptomyces sp. MADO2 and Nocardiopsis sp. MADO3 to osmotic stress in minimal medium M63 and in glycerol-asparagine medium (ISP5) was studied. The two strains were moderately halophilic and the behavior of the strain Streptomyces sp. MADO2 and Nocardiopsis sp. MADO3 towards the salt stress was varied depends on the media composition and the salinity concentration. The strain Streptomyces sp. was more sensitive to salt stress than Nocardiopsis sp. The growth of both Streptomyces sp. and Nocardiopsis sp. were inhibited at 1 M NaCl irrespective of the medium used. The Nocardiopsis sp. acquired osmoadaptation on ISP5 medium whereas the Streptomyces sp. showed poor growth on M63 medium. Glycine betaine (GB), proline and trehalose played a critical role in osmotic adaptation at high osmolarity whereas at low osmolarity they showed an inhibitory effect on the bacterial growth. The present findings confirmed that GB was the powerful osmoprotectant for Streptomyces sp. and Nocardiopsis sp. grown at 1 M NaCl both in M63 and ISP5 media.

Characterization of Leptospira borgpetersenii isolates from field rats (Rattus norvegicus) by 16S rRNA and lipL32 gene sequencing

The main goal of this study was to evaluate the prevalence of leptospirosis among field rodents of Tiruchirappalli district, Tamil Nadu, India. In total 35 field rats were trapped and tested for seroprevalence by the microscopic agglutination test (MAT). Isolation of leptospires was performed from blood and kidney tissues and characterized to serovar level. Genomospecies identification was carried out using 16S rRNA and lipL32 gene sequencing. The molecular phylogeny was constructed to find out species segregation. Seroprevalence was about 51.4 percent, and the predominant serovars were Autumnalis, Javanica, Icterohaemorrhagiae and Pomona. Two isolates from the kidneys were identified as serovar Javanica of Serogroup Javanica, and sequence based molecular phylogeny indicated these two isolates were Leptospira borgpetersenii.