Note on the nomenclature of Cassieae (Leguminosae-Caesalpinioideae) in Malaysia

As a precursor for the treatment of Caesalpiniaceae in Flora Malesiana the following new combinations are proposed: Cassia javanica ssp. pubiflora stat. nov., C. javanica ssp. agnes stat. nov., C. javanica ssp. microcalyx stat. nov. C. javanica ssp. renigera stat. nov., C. javanica ssp. bartonii stat. nov., Senna divaricata comb. nov., Chamae-christa pumila comb. nov. and Chamaechrista mindanaensis comb. nov.     

Bacterial Disproportionation of Elemental Sulfur Coupled to Chemical Reduction of Iron or Manganese

A new chemolithotrophic bacterial metabolism was discovered in anaerobic marine enrichment cultures. Cultures in defined medium with elemental sulfur (S⁰) and amorphous ferric hydroxide (FeOOH) as sole substrates showed intense formation of sulfate. Furthermore, precipitation of ferrous sulfide and pyrite was observed. The transformations were accompanied by growth of slightly curved, rod-shaped bacteria. The quantification of the products revealed that S⁰ was microbially disproportionated to sulfate and sulfide, as follows: 4S⁰ + 4H₂O → SO₄^2- + 3H₂S + 2H⁺. Subsequent chemical reactions between the formed sulfide and the added FeOOH led to the observed precipitation of iron sulfides. Sulfate and iron sulfides were also produced when FeOOH was replaced by FeCO₃. Further enrichment with manganese oxide, MnO₂, instead of FeOOH yielded stable cultures which formed sulfate during concomitant reduction of MnO₂ to Mn²⁺. Growth of small rod-shaped bacteria was observed. When incubated without MnO₂, the culture did not grow but produced small amounts of SO₄^2- and H₂S at a ratio of 1:3, indicating again a disproportionation of S⁰. The observed microbial disproportionation of S⁰ only proceeds significantly in the presence of sulfide-scavenging agents such as iron and manganese compounds. The population density of bacteria capable of S⁰ disproportionation in the presence of FeOOH or MnO₂ was high, > 10⁴ cm^-3 in coastal sediments. The metabolism offers an explanation for recent observations of anaerobic sulfide oxidation to sulfate in anoxic sediments.     

A new snailfish of the genus Careproctus (Cottoidei: Liparidae) from the Pacific coast of southern Japan

Ichthyological Research - A new snailfish, Careproctus tomiyamai, is described on the basis of four specimens collected from Suruga Bay, Tosa Bay, and the Hyuga-nada Sea, southern Japan...     

Elevated ozone decreases the multifunctionality of belowground ecosystems

Elevated tropospheric ozone (O₃) affects the allocation of biomass aboveground and belowground and influences terrestrial ecosystem functions. However, how belowground functions respond to elevated O₃ concentrations ([O₃]) remains unclear at the global scale. Here, we conducted a detailed synthesis of belowground functioning responses to elevated [O₃] by performing a meta-analysis of 2395 paired observations from 222 publications. We found that elevated [O₃] significantly reduced the primary productivity of roots by 19.8%, 16.3%, and 26.9% for crops, trees and grasses, respectively. Elevated [O₃] strongly decreased the root/shoot ratio by 11.3% for crops and by 4.9% for trees, which indicated that roots were highly sensitive to O₃. Elevated [O₃] impacted carbon and nitrogen cycling in croplands, as evidenced by decreased dissolved organic carbon, microbial biomass carbon, total soil nitrogen, ammonium nitrogen, microbial biomass nitrogen, and nitrification rates in association with increased nitrate nitrogen and denitrification rates. Elevated [O₃] significantly decreased fungal phospholipid fatty acids in croplands, which suggested that O₃ altered the microbial community and composition. The responses of belowground functions to elevated [O₃] were modified by experimental methods, root environments, and additional global change factors. Therefore, these factors should be considered to avoid the underestimation or overestimation of the impacts of elevated [O₃] on belowground functioning. The significant negative relationships between O₃-treated intensity and the multifunctionality index for croplands, forests, and grasslands implied that elevated [O₃] decreases belowground ecosystem multifunctionality.     

中国优质水果资源的分布与适宜生态环境

根据农业部在80年代两次组织评选出的全国189个优质水果产地的生态环境资料,用微型电子计算机系统建立数据库,统计分析柑桔、苹果和梨优质产品的构成比例、产区分布地域及其适宜的环境指标和主栽品种的生态适应性,为果树良种区域化栽培与选育提供依据。     

崖椒茎的化学成分

从崖椒（Zanthoxglum schinifolutm Sieb.et Zucc.)茎的石油醚、二氯甲烷提取物中分离得到8个化合物。经物理常数测定及光谱（UV,IR,MS,NMR)分析鉴定其为（1）白鲜碱（dictamning),（2）茵芋碱（skimmianine),(3)滨蒿内酯（scoparone),(4)崖椒内酯（schinifolin),(5)莨菪亭（scopoletin),（6）7-羟基-8-甲氧基香豆素（7-hydroxy-8-methoxycoumarin),（7）N-甲基弗林辛（N-methylflindersine),（8）β-谷甾醇（β-sitosterol),其中化合物（5）、（6）和（7）为首次从该植物中分离。     

RNF7 promotes glioma growth via the PI3K/AKT signalling axis

RNF7 has been reported to play critical roles in various cancers. However, the underlying mechanisms of RNF7 in glioma development remain largely unknown. Herein, the expression level of RNF7 was examined in tissues by quantitative real-time PCR, Western blotting and immunohistochemistry. The effect of RNF7 on glioma progression was measured by performing CCK-8 and apoptosis assays, cell cycle-related experiments and animal experiments. The effect of RNF7 on PI3K/AKT signalling pathway was tested by Western blotting. First, we found that RNF7 was upregulated in tumour tissue compared with normal brain tissue, especially in high-grade glioma, and the high expression of RNF7 was significantly related to tumour size, Karnofsky Performance Scale score and a poor prognosis. Second, RNF7 overexpression facilitated tumour cell cycle progression and cell proliferation and suppressed apoptosis. Conversely, RNF7 knockdown suppressed tumour cell cycle progression and cell proliferation and facilitated apoptosis. Furthermore, follow-up mechanistic studies indicated that RNF7 could facilitate glioma cell proliferation and cell cycle progression and inhibit apoptosis by activating the PI3K/AKT signalling pathway. This study shows that RNF7 can clearly promote glioma cell proliferation by facilitating cell cycle progression and inhibiting apoptosis by activating the PI3K/AKT signalling pathway. Targeting the RNF7/PI3K/AKT axis may provide a new perspective on the prevention or treatment of glioma.     

细菌吸附及转运芳香族化合物的研究进展

芳香族化合物是一类具有苯环结构的有机物,它们结构稳定,不易分解,并可通过食物链进行生物富集和生物放大,对生态环境及人类健康造成极大危害。细菌具有超强的分解代谢能力,能降解多环芳烃(polycyclic aromatic hydrocarbons, PAHs)等多种难降解芳香族污染物。吸附和转运是细菌进行芳香族化合物细胞内代谢的前提。虽然芳香族化合物的细菌降解已取得较为显著的研究进展,但吸附和转运机理仍不甚清楚。本文讨论了细菌对芳香族化合物的吸附有积极作用的细胞表面疏水性、生物被膜形成和细菌趋化性等影响因素,总结了FadL家族、TonB依赖性受体蛋白、OmpW家族等外膜转运系统和主要协同转运蛋白超家族(major facilitator superfamily, MFS)转运体、ATP结合盒(ATP-binding cassette, ABC)转运蛋白等内膜转运系统对该类化合物跨膜运输作用,并对跨膜转运机制进行了讨论和阐述,旨在为芳香族污染物的防控和治理提供一定理论参考。     

植物乳杆菌谷氨酸脱羧酶催化pH范围的理性改造及高效转化生产g-氨基丁酸

γ-氨基丁酸可由谷氨酸脱羧酶(glutamate decarboxylase, GAD)催化谷氨酸一步合成,反应体系成分简单、环境友好。然而,绝大多数GAD酶催化pH偏酸性且反应范围狭小,需要加入无机盐维持最适催化环境,增加了生产附加成分。此外,随着产物γ-氨基丁酸的生成,溶液pH会逐渐上升,不利于GAD酶的持续转化。本研究首先从实验室保藏的一株高产γ-氨基丁酸的植物乳杆菌(Lactobacillus plantarum)中克隆得到谷氨酸脱羧酶LpGAD,基于酶蛋白表面电荷修饰,选择9个位点进行定点突变及组合突变,酶学性质表征结果显示三突变体LpGAD^{S24R/D88R/Y309K}在催化pH区间内酶活力整体提高,尤其拓宽了在偏中性pH 6.0下的酶活,为野生酶的1.68倍。接下来,通过分子动力学模拟解析了酶活提高的机理。此外,将Lpgad与Lpgad^{S24R/D88R/Y309K}突变基因分别在谷氨酸棒杆菌(Corynebacterium glutamicum) E01中过表达,通过优化确定了摇瓶最适转化条件为反应温度40 ℃,菌体量OD₆₀₀=20,底物L-谷氨酸100.0 g/L,5-磷酸吡哆醛添加量为100 μmol/L。5 L发酵罐中,不调节pH,通过分批投料底物L-谷氨酸,γ-氨基丁酸产量高达402.8 g/L,较对照菌株提高了1.63倍。本研究成功拓宽了LpGAD的pH催化范围及酶活,提高了γ氨基丁酸的转化效率,为实现其规模化工业生产奠定了基础。