为提高秸秆还田过程中的腐解效率,采用CMC-Na培养基、刚果红和滤纸平板培养基分离出l株纤维素降解能力强的放线菌菌株,同时利用种子萌发法研究该菌对大豆[Glycine max (Linn.) Merr.]种子的促生作用,并分析了纤维素降解菌发酵液对大豆种子过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性以及丙二醛(MDA)含量的影响.结果 表明,分离出的菌株具有较强的分解纤维素能力,而且不同浓度的发酵液对大豆种子的萌发率和抗氧化酶活性均有影响.当发酵液浓度为100.0％时,大豆种子的萌发率达到最高值,为74.53％,与对照(不加菌液的Mendal's培养基)相比提高了21.96个百分点;大豆种子CAT和SOD活性最强,与对照相比分别提高了291.45％和106.64％;POD活性为25.6 U/(mL·min),比对照提高了101.96％,但与纯水培养相比下降了14.65％.MDA含量在发酵液浓度为16.7％时最低,与对照相比降低了21.37％.初步证实了纤维素降解菌发酵液中含有能促进大豆种子萌发和抗氧化酶活性升高的物质,以及保护膜组分的物质.

Three kinds of polysaccharides (GPⅠ, GPⅡ, GPⅢ) were separated from garlic with alkali extraction , purified by DEAE-52 cellulose column, the anticoagulant function in vitro of garlic polysaccharides was analyzed, the purity of GPⅠwas verified by SephadexG-100 and frozen-thawing-analysis, the monosaccharide constituents of GPⅠwas determined by gas chromatogram, GPC-MALLS-RI was applied to determine molecular structure of GPⅠfor the first time. Results: GPⅠ, GPⅡ and GPⅢ occupied of total garlic polysaccharides were 75.2%,15.5%,9.3%, respectively. Garlic polysaccharides had the anticoagulant function, which could effectively prolong APTT of human plasma, GPⅠworked by affecting intrinsic pathway coagulation systerm, GPⅠcontained rhamnose, fructose, galactose, glucose and mannose and unknown monosaccharide,with the constituent ratio of 1.5 ∶1.1 ∶3.3 ∶1 ∶5.1 ∶3.5, the molecular weight of GPⅠranged from 5.2×104 u to 5.6×104 u, the root mean square (rms) radius ranged from 31.5 nm to 32.9 nm, two polydispersity values were 1.039 and 1.084, respectively, It was spherical polymer. The results showed that the garlic polysaccharides had potential development value.

Using Streptococcus equi SH-0 as original strain,a mutant strain named SH-109,which was stable in heredity and could produce hyaluronic acid(HA)with high molecular weight,was achieved by 5-bromouracil(5-BU),ultraviolet and N-mEthyl-N-nitro-nitrosoguanidinc(NTG)treatments. The production conditions of high molecular weight HA were optimized by the fermentation in 500 mL flask and 5 L fermentor.According to the orthogonal test results of multi-factors,and the optimal medium for HA production was composed of 50g/L sucrose,100g/L mixed nitrogcn sources, 10g/L giucosc,2.0g/L MgSO_4·7H_2O,2.0g/L Na_2HPO_4·12H_2O,1.0g/L NaHCO_3 and 0.1g/L UTP.R was also indicated that the conditions of pH 7.6 and agitation spcod 550 r/min favored the production of HA.Under the optimized culture conditions,HA with a molecular weight of 4.36×10~6 Da was accumulated in the culture broth of mutant SH-109.

The polysaccharides components of Olong tea were isolated and purified with DEAE-52 cellulose column chromatography. Sulfation, acetylation and carboxymethylation modification were separately selected to study on anticoagulant function in vitro of purified tea polysaccharides. The results showed that tea polysaccharides possess anticoagulant function, which could effectively prolonged APTT of human plasma, but had no obvious effect on PT and TT. Four polysaccharide components were separated by column, the component Ⅱ occupied 57.36% of total tea polysaccharides and it was relatively high anticoagulant activity. The anticoagulant function of tea polysaccharides component Ⅱ was further enhanced by sulfation,acetylation and carboxymethylation modification. The proportion between chemical modification reagents and polysaccharides, and modificating reaction time influenced on the modification degree of molecular structure of tea polysaccharides, and changed the anticoagulant activity accordingly.