Halomonas binhaiensis sp. nov., isolated from saline-alkali soil.

A Gram-stain-negative, aerobic and rod-shaped bacterium, strain Y2R2T, was isolated from a saline-alkali soil sample collected from Binhai New Area, Tianjin, PR China. Growth of strain Y2R2T was observed at 10-45 °C (optimum, 30 °C), at pH 6.0-11.0 (optimum, pH 9.0) and in the presence of 0-15 % (w/v) NaCl (optimum, 9.0 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Y2R2T was affiliated with the genus Halomonas and showed the highest similarity to Halomonas huangheensis BJGMM-B45T (99.0%) and Halomonas cupida DSM 4740T (98.4%). The digital DNA-DNA hybridization and average nucleotide identity values of 21.0-22.8 % and 73.3-75.7 % with the closely related species H. huangheensis BJGMM-B45T, H. cupida DSM 4740T, H. ventosae AL12T, H. stenophila N12T and H. litopenaei SYSU ZJ2214T were lower than the threshold recommended for species discrimination.The major respiratory quinone of strain Y2R2T was Q-9 and the major cellular fatty acids consisted of C16 : 0, C19 : 0 cyclo ω8c and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The DNA G+C content of strain Y2R2T was 57.0 mol%. On the basis of this polyphasic taxonomic study, strain Y2R2T is considered to represent a novel species of the genus Halomonas, for which the name Halomonas binhaiensis sp. nov. is proposed. The type strain is Y2R2T (=CGMCC 1.16974T=KCTC 72578T).

The pH-responsiveness carrier of sanxan gel beads crosslinked with CaCl2 to control drug release.

Natural polysaccharide-based gel carriers have been widely studied for their potential to provide slow and controlled release. Sanxan is an edible polysaccharide produced by Sphingomonas sanxanigenens. In this study, gel beads were prepared using the extrusion dripping method with sanxan as the carrier material and HCl and CaCl2 as the fixing solution. The molecular structure, texture profile, and microstructure of the bead were analyzed. And the swelling characterization and in vitro release of beads were evaluated. The results of Fourier-transform infrared analysis indicate that Ca2+ was used to create an ionically crosslinked structure of sanxan. Texture analyzer and scanning electron microscope studies showed that the acid­calcium gel exhibited physical resistance and resilience, as well as a distinct gel pore structure. The swelling, dissolution, and drug release of the beads decreased as the amount of CaCl2 increased. Compared to the control (without CaCl2), the release of sanxan beads when 0.5 CaCl2 was added (sanxan carboxyl/Ca2+, by the number of moles M/M) in the stomach and small intestine release decreased by 40.9 % and 49.5 %, respectively. This study indicates that the fabrication of sanxan-Ca2+ crosslinked gel had sustained release characteristics, indicating that sanxan carriers have great potential for gradual and regulated medication delivery.

Preparation and properties of Sanxan gel based fertilizer for water retention and slow-release.

The advent of gel fertilizers has benefited agriculture and the environment. This study utilized sanxan, a novel polysaccharide, as a carrier and loaded it with urea to create sanxan gel fertilizer (SGF), thus creating a new, effective gel fertilizer. Water retention and sustained release ability of SGF were evaluated, and crop experiments were carried out. The results showed that, SGF that content 2.0 % solution of sanxan and loaded 20 g g-1 of urea were prepared by heating-cooling method. The water-retention ratio of SGF was attained at 56.4 g g-1 for 10 h. The urea releases of SGF in water have a more significant persistence than pure urea. In addition, wheat growth was promoted by SGF, compared with pure urea, the biomass of wheat shoot and root increased 27.4 % and 62.2 % during 20 days, respectively. Consequently, SGF has the ability to retain water and slowly release nutrition, which was an ideal carrier for managing water and urea. The SGF developed in this study provides data support and theoretical basis for the application of sanxan gel in agriculture and the environment.