Meng Y.,Shaanxi Normal University |
Dong G.,Shaanxi Normal University |
Zhang C.,Shaanxi Normal University |
Ren Y.,Shaanxi Normal University |
And 2 more authors.
Objective: To study the effect of Ca2+ on glutamate dehydrogenase (GDH) and its role in poly-γ-glutamic acid (γ-PGA) synthesis in Bacillus natto HSF 1410. Results: When the concentration of Ca2+ varied from 0 to 0.1 g/l in the growth medium of B. natto HSF 1410, γ-PGA production increased from 6.8 to 9.7 g/l, while GDH specific activity and NH4Cl consumption improved from 183 to 295 U/mg and from 0.65 to 0.77 g/l, respectively. GDH with α-ketoglutarate as substrate primarily used NADPH as coenzyme with a Km of 0.08 mM. GDH was responsible for the synthesis of endogenous glutamate. The specific activity of GDH remained essentially unchanged in the presence of CaCl2 (0.05–0.2 g/l) in vitro. However, the specific activity of GDH and its expression was significantly increased by CaCl2 in vivo. Therefore, the regulation of GDH and PGA synthesis by Ca2+ is an intracellular process. Conclusion: Calcium regulation may be an effective approach for producing γ-PGA on an industrial scale. © 2015, Springer Science+Business Media Dordrecht. Source
Guo S.,Northwest University, China |
Ji W.,Massey University |
Li M.,CAS Institute of Zoology |
Chang H.,Northwest University, China |
And 2 more authors.
American Journal of Primatology
This article reports the first genetic study of the mating system of the Sichuan snub-nosed monkey (Rhinopithecus roxellana), an endemic and endangered species in China. The investigation was carried out in a population (WRT) in the Qinling Mountains using data from both field observation and paternity analysis through microsatellite DNA profiling. During a mating season, a male on an average copulated with 5.7 females. Approximately 18% of the females were observed to copulate with more than one male over the study period. The majority of copulations (94.5%) were initiated by females. Twenty-eight of 430 observed matings were extra-unit copulations. Eight polymorphic microsatellite loci were used for paternity analysis. The number of alleles at each locus ranged from 3 to 7 (mean54.3). Observed heterozygosity ranged between 0.32 and 0.79. None of the loci showed significant deviation from Hardy-Weinberg equilibrium. Results from paternity exclusion showed that 12 of 21 (57.1%) immature individuals were sired by extra-unit males. Although the basic social unit of snub-nosed monkeys is consistent with a polygynous mating system, both field observation and genetic data suggests that their mating system is polygamous. Infanticide and inbreeding avoidance are the most likely explanations for the promiscuity of female snub-nosed monkeys. © 2009 Wiley-Liss, Inc. Source
Wang C.L.,shanxi Academy of science |
Wang X.W.,shanxi Academy of science |
Qi X.,Northwest University, China |
Zhao H.T.,shanxi Academy of science |
And 4 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica
Group living provides various advantages to individuals such as predator protection, improved competiveness against conspecific groups for resources, and better breeding and exchange of information. However, close spatial proximity commonly comes with costs in the form of increased competition between individuals over limited resources within the group. In the competion, unless a decision is reached among indivudals, the group will split apart and indivuduals will loss advantages in group living. To keep the group cohesive, self-organization and leadership are two means of coordination and two types of decision can be made on the group level: combined decision and consensus decision. Here we briefly review the types of group decisions, the coordination mechanisms of competition within group and the process of group decision making. We also compare the effect of information and interest in group decision making. We tend to provide backgrounds to further studies on group decision and advices for conservation in group-living animals. Source