菠萝渣淀粉功能降解菌筛选及s2b7-4的鉴定

为了加快菠萝渣发酵,本试验通过利用多种选择性培养基,从自然发酵的菠萝渣中分离到多种淀粉分解菌,经过初筛和复筛,获得了降解菠萝渣的淀粉降解功能菌株s2b7-1和s2b7-4,筛选出其最适培养基为改良LB培养基及其优化组合。通过形态、生理生化和分子综合鉴定得出s2b7-4菌株为枯草芽胞杆菌(Bacillus subtilis)。     

甘蔗渣纤维素降解菌的筛选及鉴定

通过利用多种选择性培养基,从自然发酵不同阶段的甘蔗渣中分离到多种纤维素分解菌,经过初筛和复筛,获得了降解纤维素的功能菌株c1g3-3及其最适功能培养基蛋白胨纤维素培养基（PCS）,并通过形态、生理生化和分子综合鉴定得出c1g3-3鉴定为木糖氧化无色杆菌（Achrom obacter xylosoxidans）。     

更正

本刊2010年第6期刊登的贺军军、罗萍等文章"菠萝渣淀粉功能降解菌筛选及s2b7-4"及2011年第1期刊登的贺军军、罗萍等文章"甘蔗渣纤维素降解菌的筛选及鉴定",应作者本人要求,文中作者单位排序修改为"1.中国热带农业科学院湛江实验站;2.中国热带农业科学院环境与植物保护研究所;     

产自Aspergillus sp. DLCS-F18的嗜酸嗜热纤维素酶及其酶学性质

纤维素酶在饲料、造纸、纺织和纤维素乙醇生产等领域有重要用途,因而备受关注。使用稻草为唯一碳源进行纤维素降解微生物的富集,从云南大理苍山地区的土壤样品中筛选获得1株纤维素降解真菌DLCS-F18,其适宜生长温度为15-40℃、pH 2.0-13.0。通过形态学和ITS rRNA分子生物学鉴定,菌株DLCS-F18被鉴定为曲霉属菌株Aspergillussp.。使用稻草发酵培养基进行诱导,发现该菌株所产纤维素酶的最适pH为4.0,最适温度为65℃,在pH 3.0保持85%的活性,在75℃保持70%以上的活性,在大多数金属离子和酶抑制剂存在的条件下活性表现稳定。菌株发酵84h的上清对羧甲基纤维素钠（CMC-Na）的最高活性为(5.4±0.2)U/mL。这说明DLCS-F18所分泌的纤维素酶是嗜酸嗜热纤维素酶,其酶学特性预示着菌株在木质纤维素水解和动物饲料中具有广阔的应用前景。     

羊毛生物整理复合酶L86发酵工艺优化研究

采用L9（34）正交试验对L86复合酶生产菌的发酵培养基进行优化、并通过溶氧浓度调节和中期补加蛋白水解液对发酵过程进行调控。结果表明较优的培养基组成为（g/100ml）：黄豆粉4.0、玉米粉1.0、鱼粉0.6、蚕蛹粉0.6、CaCl20.5、NH4Cl1.0、Na2HPO4·2H2O 0.4;通气量控制30h前1:0.5、30-50h1:1.0、50h后1:1.2 v/v/m。在上述条件下摇瓶,酸性蛋白酶酶活10000u/ml、纤维素CMC酶3600u/ml;在0.5m3搅拌罐中扩大中试平均发酵单位酸性蛋白酶5500u/ml、纤维素CMC酶2200u/ml。     

羊毛生物整理复合酶L86发酵工艺优化研究

采用L9（9^4)正交试验对L86复合酶生产菌的发酵培养基进行优化、并通过溶氧浓度调节和中期补加蛋白水解液对发酵过程进行调控,结果表明罪状优的培养基组成为（g/100ml);黄豆粉4.0、玉米粉1.0、鱼粉0.6、蚕蛹粉0.6、CaCl20.5、NH4Cl1.0、Na2HPO4.2H2O0.4;通气量控制30h前1：0.5、30-50h1:1.0、50h,后1：1.2v/v/m。在上述条件下摇瓶,酸性蛋白酶酶活10000u/ml、纤维素CMC3600u/ml;在0.5m^3搅拌罐中扩大中试平均发酵单位酸性蛋白酶5500u/ml、纤维素CMC酶2200u/ml。     

侧孢霉液体深层发酵生产木质纤维素分解酶

近年来,直接利用农业秸秆及其废弃物通过微生物转化生产纤维素酶和蛋白饲料引起了广大的关注（Buswelletal,1996,okekeetal,1993）。但目前对木质素分解酶的研究报导很少。本文采用7L搅拌式发酵罐,对侧抱霉（砂orotrichumsp．）直接利用甜菜渣液体深层发酵生产木质纤维素分解酶及酶反应条件进行了初步探讨。l材料与方法1．l菌种和培养条件侧抱震（》orotrichumsp）由中国农科院原子能利用研究所提供。菌株PDA斜面在4℃冰箱条件下保存,用于本项研究。液体种子培养基（g／L）：结晶纤维素10;酵母粉l;无机盐溶液10ml。发酵培养基（g…     

剥粒菠萝组织培养及快速繁殖的研究

剥粒菠萝是目前菠萝品种中最适于鲜食的良种之一。本研究以剥粒菠萝为材料 ,通过 1 0种培养基的诱导筛选、繁殖生根 ,从中选出最适宜剥粒菠萝组培快繁的一整套稳定、高效的生产程序 ,即 :芽诱导培养基为MS 6_BA 3mg/L(单位下同 ) NAA 0 .1 ,增殖培养基为MS 6_BA 4 NAA 0 .1 ,生根培养基为 1 /2MS 6_BA 2 NAA 0 .2 活性炭 0 .1 %。该组培技术的成功 ,为规模化生产剥粒菠萝提供了快速繁殖种苗的技术保障 ,有利于促进南方地区名优水果的发展 ,有利于南方农业结构的产业化调整。     

解淀粉芽孢杆菌MN-8对玉米秸秆木质纤维素的降解

微生物降解木质纤维素既是生物质资源化利用中的关键问题,也是亟需解决的难点问题.本文在前期获得木质素降解菌——解淀粉芽孢杆菌MN-8菌株的基础上,进一步研究该菌株对玉米秸秆木质纤维素的降解作用.研究利用玉米秸秆粉-MSM培养基对MN-8菌株进行固态发酵,监测发酵过程中木质纤维素酶活力和木质纤维素含量变化情况,并通过傅立叶红外光谱(FTIR)和气质联用色谱(GC/MS)对木质纤维素的降解情况及产物进行分析.结果表明:解淀粉芽孢杆菌MN-8菌株可产生木质素过氧化物酶、锰过氧化物酶、纤维素酶和半纤维素酶等木质纤维素降解酶,在发酵10～16 d陆续达到酶活力峰值,最高酶活力分别为55.0、16.7、45.4和60.5 U·g-1.发酵24 d后,玉米秸秆中木质素、纤维素和半纤维素的降解率可分别达到42.9％、40.6％和27.1％.FTIR光谱数据表明,玉米秸秆发酵后木质素、纤维素和半纤维素的特征吸收峰强度均有一定程度的下降,表明木质纤维素被部分降解.GC/MS分析结果也证实,解淀粉芽孢杆菌MN-8能有效降解秸秆木质纤维素.MN-8菌株可断裂玉米秸秆木质素单体之间的连接键β-O-4,将秸秆木质素解聚为苯丙胺、苯丙酮和苯丙酸等保留木质素苯丙烷结构的单体化合物,并将部分单体化合物进一步氧化为Cα羰基化合物,如2-氨基-1-苯丙酮和紫丁香基苯乙酮等.在对纤维素和半纤维素降解产物的GC/MS分析中发现,降解产物包含葡萄糖、甘露糖和半乳糖等多种单糖化合物以及甲酸、乙酸、丙酸、1,1-乙二醇和3-羟基丁酸等代谢产物.表明解淀粉芽孢杆菌MN-8对秸秆木质纤维素表现出强降解作用,且该作用依赖于菌株产木质纤维素降解酶的能力.     

鸡尾酒δ整合策略构建表达三类纤维素酶的酿酒酵母工程菌株及初步评价

木质纤维素乙醇具有替代化石燃料的潜力,其生产过程包括生物质预处理、纤维素酶生产、水解和发酵等多个步骤。将纤维素酶生产、水解和发酵组合在一起的统合生物加工过程（consolidated bioprocessing,CBP）由于能降低水解和发酵成本而具有应用于纤维素乙醇生产的潜力,该技术的关键是构建能有效降解纤维素的工程菌株,而构建表达纤维素酶的酿酒酵母即是其中一种选择。采用鸡尾酒多拷贝δ整合的策略将7种纤维素酶基因（Trichoderma reesei cbh1、cbh2和egl2,Aspergillus aculeatus cbh1、egl1和bgl1）表达盒整合至酿酒酵母W303-1A染色体上,经4轮整合筛选得到菌株LA1、LA2、LA3和LA4。对这4个菌株进行纤维素酶活性测定,结果表明从LA1到LA3各种纤维素酶活性呈递增趋势,而LA4的酶活性与LA3的酶活水平相当。对菌株LA3进行酸碱预处理玉米芯料的发酵评价,结果表明：①在外加商品化纤维素酶的情况下,与对照菌株W303-1A和AADY相比,LA3能有效利用纤维素料发酵产醇;②与分步整合的菌株W3相比,发酵性能更优;③培养基中的营养成分影响菌株发酵性能。这些结果表明,鸡尾酒δ整合是一种有效的构建酿酒酵母CBP菌株的方法。     

Production of phenolic antioxidants by the solid-state bioconversion of pineapple waste mixed with soy flour using Rhizopus oligosporus

The ability of Rhizopus oligosporus to produce enhanced levels of free phenolics from pineapple residue mixed with soy flour as potential nitrogen source was investigated. Concurrently, phenolic-linked β-glucosidase and the antioxidant activity of the extracts were followed. Two treatments were studied: (A) 9 g of pineapple residue and 1 g of soy flour (P9); (B) 5 g of pineapple residue and 5 g of soy flour (P5). The increase of water extractable phenolics was 39.3% for P9 treatment and 79.4% for P5 treatment. During early stages of growth high antioxidant activity, low phenolic content and low β-glucosidase specific activity was observed. High antioxidant activity was likely due to the presence of insoluble polymeric phenolics, know for their high antioxidant activity. A marked decrease of the antioxidant activity of P5 treatment during late stages of growth was observed due to likely formation of free soluble phenolics. The moderate total phenolics content and high β-glucosidase specific activity of P9 treatment in late stages is likely the consequence of low nitrogen content in this treatment. The bioconversion of pineapple residue by R. oligosporus leads to enhanced levels of phenolic compounds, mainly for P5 treatment. This approach offers a novel strategy to enhance the value of pineapple wastes.     

Production of bacterial cellulose from <Emphasis Type="Italic">Enterobacter amnigenus</Emphasis> GH-1 isolated from rotten apple

Bacterial cellulose finds novel applications in biomedical, biosensor, food, textile and other industries. The optimum fermentation conditions for the production of cellulose by newly isolated Enterobacter amnigenus GH-1 were investigated. The strain was able to produce cellulose at temperature 25–35°C with a maximum at 28°C. Cellulose production occurred at pH 4.0–7.0 with a maximum at 6.5. After 14 days of incubation, the strain produced 2.5 g cellulose/l in standard medium whereas cellulose yield in the improved medium was found to be 4.1 g/l. The improved medium consisted of 4% (w/v) fructose, 0.6% (w/v) casein hydrolysate, 0.5% (w/v) yeast extract, 0.4% (w/v) disodium phosphate, and 0.115% (w/v) citrate. Addition of metal ions like zinc, magnesium, and calcium and solvents like methanol and ethanol were found to be stimulatory for cellulose production by the strain. The strain used natural carbon sources like molasses, starch hydrolysate, sugar cane juice, coconut water, coconut milk, pineapple juice, orange juice, and pomegranate juice for growth and cellulose production. Fruit juices can play important role in commercial exploitation of bacterial cellulose by lowering the cost of the production medium.     

Carotenoid production by Xanthophyllomyces dendrorhous: use of pineapple juice as a production medium

Aims:  To select a carotenoid-hyperproducing mutant and to formulate pineapple juice as a carotenoid production medium.
Methods and Results:  Yeast strain of Xanthophyllomyces dendrorhous mutant GM 807 (derived from gamma irradiation) and the mutant n78 (from neutron irradiation) were selected based on higher carotenoid production in diluted pineapple juice as a medium. The selected strain was evaluated under various concentrations of pineapple juice. The results obtained in the study demonstrate that the mutant GM 807 enhanced production by 65·8% when using pineapple juice as medium at 10% dilution in place of yeast malt medium.
Conclusion:  Pineapple juice could be used as a sole medium for carotenoid production.
Significance and Impact of the Study:  Our results provide useful information for the design of production media for carotenoids to be used in various applications.     

菠萝种质的离体保存研究

以菠萝品种巴厘"的组培苗为试验材料,在常温下通过改变MS培养基中无机盐和蔗糖含量,选择适合菠萝种质保存的培养基.对不同保存培养基中菠萝苗叶色的变化、小苗的生长及存活等进行了调查分析.结果显示,菠萝种质在M2(1/2MS 0.7%琼脂)中保存12个月存活率为92.2%,小苗的平均生长量只有1 cm左右;保存苗转入分化培养基后,很快恢复生长并分化出丛芽.在M2中保存18个月后仍有较高存活率(85.7%).表明M2是菠萝种质保存的最佳培养基.     

Biosynthesis of hetero-polysaccharides by Acetobacter xylinum - Synthesis and characterization of metal-ion adsorptive properties of partially carboxymethylated cellulose

Biological reconstruction of water-soluble carboxymethylated cellulose (CMC; D.S. =0.47) has been achieved by culturing Acetobacter xylinum in medium containing CMC and -glucose to give a novel hetero-polysaccharide having a carboxymethyl function. The novel extracellular polysaccharide, carboxymethylated-bacterial cellulose (CM-BC), had an ion exchange ability with enhanced specific adsorption for lead and uranyl ions compared to the original CMC and bacterial cellulose. The contribution of the hydroxy group at C-2 was confirmed by applying carboxymethylated chitin, which possesses acetamido group at C-2 of the glucose residue, as the carbon source of the incubation.     

Carbon Flux and Carbohydrate Gene Families in Pineapple

The recently sequenced pineapple genome was used to identify and analyze some of the key gene families involved in carbohydrate biosynthesis, breakdown and modification. Gene products were grouped into glycosyltransferases (GT), glycoside hydrolases (GH), carbohydrate esterases (CE), and polysaccharide lyases (PL) based upon predicted catalytic activity. Non-catalytic carbohydrate-binding modules (CBM) and enzymes involved in lignification were also identified. The pineapple genes were compared with those from two and five monocot and eudicots species, respectively. The complement of pineapple sugar and cell wall metabolism genes is similar to that found in rice and sorghum, though the numbers of GTs and GHs is often fewer. This applies to a lesser extent to the genes involved in nucleotide-sugar interconversion, with both pineapple and papaya having a minimum complement. Interestingly, pineapple does not appear to contain mixed linkage β-glucan in its walls while possessing cellulose synthase-like (Csl), J and H genes. Pineapple and papaya have less than half the number of GT1 genes involved in small molecule glycosylation compared to Arabidopsis and tomato, and fewer members in GH families than Arabidopsis. The ratio of rice and sorghum to pineapple genes in GH families was more variable than in the case of GTs and it is unclear why pineapple GH gene numbers are so low. Rice, sorghum and pineapple have far fewer CE8, PL1 and GH28 genes related to pectin metabolism than most eudicots. The general lower number of cell wall genes in pineapple possibly reflects the absence of a genome duplication event. The data also suggests that pineapple straddles the boundary between grasses (family Poaceae) and eudicots in terms of genes involved in carbohydrate metabolism, which is also reflected in its cell wall composition.     

The effect of learning on experimental evolution of resource preference in Drosophila melanogaster

Abstract Learning is thought to be adaptive in variable environments, whereas constant, predictable environments are supposed to favor unconditional, genetically fixed responses. A dichotomous view of behavior as either learned or innate ignores a potential evolutionary interaction between the learned and innate components of a behavioral response. We addressed this interaction in the context of oviposition substrate choice in Drosophila melanogaster, asking two main questions. First, will learning also evolve in a constant environment in which it always pays to show the same choice? Second, how does an opportunity to learn affect the evolution of the innate (genetic) component of oviposition substrate choice? We exposed experimental populations to four selection regimes, involving selection on oviposition substrate preference (an orange versus a pineapple medium). In two selection regimes the flies were selected for preference either for the orange medium, or for the pineapple medium. In the remaining two selection regimes the flies were also selected for preference for either orange or pineapple, but additionally could use past experience (aversion learning) to decide which medium it paid to avoid. Lines exposed to the latter selection regimes evolved improved learning ability, indicating that learning may be advantageous even if the same behavioral response is favored every generation. Furthermore, of the two selection regimes that favored oviposition on the pineapple medium, the regime that allowed for learning led to the evolution of a stronger innate preference for pineapple, than the regime that did not allow for learning. In contrast, of the two regimes that selected for oviposition on the orange medium, the one that allowed for learning led to a smaller evolutionary change of the innate preference. Thus, an opportunity to learn facilitated the evolution of innate preference under selection for preference for pineapple, but hindered it under selection for preference for orange. We discuss possible mechanisms for this effect.     

林业剩余物资源量评估所用系数的定义和取值

有机废弃物是重要的待开发利用的生物质资源,特别是发展生物炼制。文中针对林业剩余物第二级分类的全部10个类型,根据1993–2017年间报道的有关林业剩余物系数研究,首先在前人研究结果的基础上,完善了系数体系及其定义。然后,对以前的取值通过文献溯源甄别其合理性,对于没有明确依据的取值和迄今未取值的系数,通过相关研究获得数据并进行实地调研,确定了计算林木苗圃剩余物、林木修枝剩余物、木材采伐剩余物、木材造材剩余物、木材加工剩余物、竹材加工剩余物、薪材、废旧竹材和废旧木材、香蕉和菠萝残体所需系数的合理取值。     

Double-phase culture system for large scale production of pineapple

We have developed an efficient and simplified method for shoot proliferation of the pineapple (Ananas comosus L.), using a Double-Phase Culture System (DPS) (semi-solid medium with a layer of liquid medium on the top). Under these conditions, up to 430 microshoots were produced from 5 initial shoots within 5 months, and without shoot manipulation. Thus, >50% shoots proliferated as compared to that on agar-solidified medium. Shoots taken from DPS were rooted within 4 weeks at a frequency of up to 100%, in full-strength or half-strength Murashige and Skoog medium containing 0.5–2.5 μM indole-3-butyric acid. The plantlets were then transferred into soil, and they survived acclimatization with 100% success. Thus, DPS could be useful for large-scale micropropagation of a range of pineapple cultivars, with high production of plantlets at the end of process, and reduced labor costs during the subcultures.