Simultaneous Removal of Mn(II) and Nitrate by the Manganese-Oxidizing Bacterium Acinetobacter sp. SZ28 in Anaerobic Conditions

A novel bacterium, strain SZ28, identified as Acinetobacter sp., showed anaerobic denitrification ability using Mn(II) as the electron donor. Nitrate-nitrogen concentration decreased from nearly 16.52–mg L^?1 to 4.4–mg L^?1, without accumulation of nitrite as an intermediate, with a maximum of 0.063–mg NO₃^?-N L^?1 h^?1, reaching a peak of 0.085–mg NO₃^?-N L^?1 h^?1 in sodium acetate. The nitrate removal rate reached 0.067–mg NO₃^?-N L^?1 h^?1, 0.059–mg NO₃^?-N L^?1 h^?1, and 0.078 mg NO₃^?-N L^?1 h^?1 using Mn(II), S(II), and Fe(II) as electron donors, respectively. The optimum pH was 6.0, with a removal rate of 0.063–mg NO₃^?-N L^?1 h^?1     

Acidogenic growth model of embryogenic cell suspension culture and qualitative mass production of somatic embryos from triploid bananas

A young male flower-derived embryogenic suspension cell population of AAA ‘Pei Chiao’, ‘Dwarf Cavendish’, and AAB ‘Raja’ was used for developing an acidogenic growth model . We hypothesized that a close relationship exists between the self-regulated pH medium and the corresponding changes in the growth phases. Studies have reported that a pH below 4.6 may prevent the embryogenic cells from undergoing polar growth. Controlling pH up to a level 4.6 within 2 days during the changes of pre-embryogenic cells (PECs) and proembryogenic masses into embryogenic determined cells (EDCs) uniformly resulted in unequal cell division. The hydrogen ion buffer 2-N-morpholino-ethanesulfonic acid at 10 g L⁻¹ was added to MA2 and MA3 media, showing the medium pH of MA3 up to 5.0, thus maintaining a relatively stable pH in AAA ‘Pei-Chiao’ and AAB ‘Raja’ cells that autoregulate acidification, significantly increasing the number of somatic embryos. When the proliferation and globularization phases were acidified to pH 3.5 ± 0.2, cells were released to free single cells of PECs and EDCs after 21 days. This study provides possible explanation that PECs deposit callose on their cell walls as a possible protector from strong acidic condition. Regulation at pH 5.0 ± 0.2 resulted the production efficiency achieved was 0.9 million somatic embryos per 1 mL of the settled cell volume.

     

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...     

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.