A Gram-stain-negative, aerobic, non-endospore-forming organism, isolated from the rhizosphere sand of a coastal sand dune plant was studied for its taxonomic position. On the basis of 16S rRNA gene sequence similarity comparisons, strain YU-PRIM-29 was grouped within the genus Halomonas and was most closely related to Halomonas johnsoniae (97.5 %). The 16S rRNA gene sequence similarity to other Halomonas species was <97.5 %. Strain YU-PRIM-29 grew optimally at 28 °C (growth range, 10-36 °C), at a pH of 7-9 (growth range, pH 5.5-12.0) and in the presence of 0.5 to 5 % (w/v) NaCl (growth up to 20 % NaCl). The fatty acid profile from whole-cell hydrolysates supported the allocation of the strain to the genus Halomonas. The fatty acids C18 : 1ω7c and C16 : 0 were found as major compounds, followed by the hydroxylated fatty acid C12 : 0 3-OH. The quinone system consisted predominantly of ubiquinone Q-9. The polar lipid profile was composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. In the polyamine pattern, spermidine was the predominant compound. The DNA G+C content was 64.8 mol%. In addition, the results of physiological and biochemical tests also allowed phenotypic differentiation of strain YU-PRIM-29 from its closest-related species. Hence, YU-PRIM-29 represents a new species of the genus Halomonas, for which we propose the name Halomonas malpeensis sp. nov., with YU-PRIM-29 (=LMG 28855=CCM 8737) as the type strain.

In this study, bacteria associated with marine organisms were screened for the production of exopolysaccharides (EPSs) on MY media containing sea salts (2.5%10%). Three selected isolates were identified as Alteromonas sp. PRIM-21, Nitratireductor sp. PRIM-24 and Enterobacter sp. PRIM-26 using 16S rRNA gene sequencing. Optimization of the growth and EPS production kinetics in relation to incubation time were assessed. The purified EPS yield was 590, 650 and 540 mg·L 1 culture media respectively in Alteromonas sp. PRIM-21, Nitratireductor sp. PRIM-24 and Enterobacter sp. PRIM-26. Biochemical and FTIR analyses revealed the presence of biologically important functional groups in the EPS produced by all the three isolates. The EPS produced by Nitratireductor sp. PRIM-24 and Alteromonas sp. PRIM-21 showed 2.0% sulfate content. These bacterial EPS also showed antioxidant and emulsifying activities and the EPS produced by Enterobacter sp.PRIM-26 showed significantly higher antioxidant activities in terms of superoxide (IC 50 0.33 mg·mL 1 ) and DPPH (IC 50 0.44 mg·mL 1 ) radical scavenging. It also showed higher emulsifying activities against selected hydrophobic substrates with EI 24 values above 60%. From the results of the study, it can be concluded that the isolated bacteria produce EPS that can be investigated in detail for biotechnological applications.

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The particular exploration includes the two-dimensional Casson nanoliquid motion predicaments, adjacent to the boundary level over the stretching sheet via non-Darcian porous medium. A particular computational description is given for the governing boundary value problem pertaining to nonlinear partial differential equations relating to momentum, thermal and mass transfer which are computed by fourth-order Runge–Kutta and shooting approaches. The brunt of several parameters like viscous dissipations, magnetic field, porous parameter, thermal diffusivity, Brownian diffusion coefficient and Casson fluid parameter on momentum, heat as well as mass transfer is explored. Moreover, it was noticed that liquid motion is repelled by the Forchheimerr parametric quantity resulting in a reduction in velocity magnitude, within the boundary layer, whereas in the thermic boundary layer, there is an increase in the thermal profile. Furthermore, when the value of the Brownian motion parameter increases, the axial velocity drops, but the thermophoresis parameter is said to have the opposite effect.