Erratum to: Research advances in expansins and expansin-like proteins involved in lignocellulose degradation

Biotechnology Letters -     

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.