Insights into functional genes and taxonomical/phylogenetic diversity of microbial communities in biological heap leaching system and their correlation with functions

Applied Microbiology and Biotechnology - Although the taxonomical/phylogenetic diversity of microbial communities in biological heap leaching systems has been investigated, the diversity of...     

Enrichment and characteristics of mixed methane-oxidizing bacteria from a Chinese coal mine

In methane-rich environments, methane-oxidizing bacteria usually occur predominantly among consortia including other types of microorganisms. In this study, artificial coal bed gas and methane gas were used to enrich mixed methanotrophic cultures from the soil of a coal mine in China, respectively. The changes in microbial community structure and function during the enrichment were examined. The microbial diversity was reduced as the enrichment proceeded, while the capacity for methane oxidation was significantly enhanced by the increased abundance of methanotrophs. The proportion of type II methanotrophs increased greatly from 7.84 % in the sampled soil to about 50 % in the enrichment cultures, due to the increase of methane concentration. After the microbial community of the cultures got stable, Methylomonas and Methylocystis became the dominant type I and type II methanotrophs, while Methylophilus was the prevailing methylotroph. The sequences affiliated with pigment-producing strains, Methylomonas rubra, Hydrogenophaga sp. AH-24, and Flavobacterium cucumis, could explain the orange appearance of the cultures. Comparing the two cultures, the multi-carbon sources in the artificial coal bed gas caused more variety of non-methanotrophic bacteria, but did not help to maintain the diversity or to increase the quantity and activity of methanotrophs. The results could help to understand the succession and interaction of microbial community in a methane-driven ecosystem.     

Length–weight and length–length relationships of seven fish species from the Ili River and tributaries,northwest China

Length–weight and length–length relationships were estimated for seven fish species belonging to four families from the Ili River and its tributaries, northwest China. From April to October 2013 and May to October 2014, specimens were collected monthly for a total of 783 specimens. This study presents the first references on LWRs for Diptychus maculates, Gymnodiptychu dybowskii, Perca schrenkii, Silurus meridionalis and Schizothorax pseudoaksaiensis pseudoaksaiensis, and LLRs for G. dybowskii, P. schrenkii, S. meridionalis, S. pseudoaksaiensis pseudoaksaiensis, Triplophysa strauchii and Triplophysa stoliczkai.     

Ultrasonic Reaction of Bank Vole Males to the Presence of Females Varying in Hormonal Activity

Rodents are known to emit ultrasounds during social interactions. Despite the evidence that ultrasonic vocalizations are emitted during sexual encounters and may play a certain role in sexual selection, only a few studies have investigated this phenomenon, mainly in laboratory rodents. We analysed the ultrasonic calls of bank vole (Myodes glareolus) males from an outbred colony in the presence of females differing in hormonal activity. Sexually experienced males were tested during interactions with naive, ovariectomized, pregnant and post‐partum oestrous females. We found that the males’ ultrasound vocalizations depend on the phase of the bank vole females’ reproductive cycle. During encounters with post‐partum oestrous females the males emitted significantly more ultrasounds, and the total duration of ultrasound vocalization was longer. The presence of post‐partum oestrous females also influenced the type of ultrasounds: the most typical constant‐frequency sounds were significantly shorter, and two additional types of ultrasounds were presented during interactions with females ready to mate: U‐shaped frequency‐modulated sounds and frequency‐modulated upsweep sounds. To our knowledge this is the first evidence that male voles of the subfamily Arvicolinae emit different types of ultrasounds in the presence of females depending on their reproductive stage. We suggest that these ultrasounds may be employed as an attractant during reproductive behaviour and that they are potentially an element of sexual selection.