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Abstract An alkaline active L-glutaminase (BALG) producing bacterium was screened and identified from seamount sediment samples of the Arabian Sea. The isolate was confirmed to be Bacillus australimaris NIOT30 based on morphological characteristics and 16 S rRNA gene sequencing. The glutaminase gene, balg was PCR amplified, cloned and expressed in E. coli BL21 (DE3) host. The molecular weight of purified BALG was estimated to be 36 kDa and the enzyme showed a specific activity of 507 ± 27 Umg−1 against L-glutamine under optimal assay conditions of pH 7.0 and temperature at 37 °C for 15 min. The enzyme showed maximum activity at pH 7 and retained 95% activity at pH 10. BALG retained a relative activity of about 82% and 45% at 45 °C and 60 °C respectively. The kinetic parameters of BALG, Km and Kcat/Km were determined to be of 210 ± 11 mM and 4.4 × 102 M s−1 respectively. Homology modeling and substrate ligand interaction studies revealed the stability of the enzyme-substrate complex. The present study highlights the characterization of a highly active L-glutaminase from B. australimaris NIOT30. Further, mutational analyses of ligand binding residues would show insights into the affinity of L-Glutaminase.

We describe here a new species of terrestrial earthworm Eutyphoeus rihnimensis sp. nov. (family Acanthodrilidae) from specimens collected at Khawrihnim, a village in Mizoram, Northeast India. The new species is distinguished from its congener members in E. gigas group in having an outgrowth that branches into four finger-like projections from the male porophores, five pairs of supra-intestinal glands in 8188 segments, typhlosole that begins from segment 25, ventral intestinal caeca 10 that covers segments 33-34, a bidiverticulate spermathecae with a short and stout duct, and very short lateral and median diverticula among other characters. Sequence analysis based on mitochondrial cytochrome c oxidase subunit 1 (CO1) gene further warrants its distinction from known species of Eutyphoeus.