Several Fine Brewer’s Yeast Strain Screening and Their Pilot Scales

啤酒酵母菌种是啤酒生产的关键。因此选育优良的啤酒酿造酵母菌株是啤酒工业的一项重要任务。本研究采用物理化学诱变和原生质体融合的方法，选育具有低产双乙酰、乙醛和总高级醇等优良特性的啤酒酿造酵母菌株。 啤酒酵母（Saccharomycescerevisiae）XB05经半导体激光诱变，筛选得到一株发酵特性优良的菌株JY2-2。突变株JY2-2的500L发酵罐发酵试验和120t、240t、360t发酵罐生产性试验结果均表明，该菌株具有发酵能力强，双乙酰还原速度快，发酵液中的双乙酰、乙醛和总高级醇的含量较低等特性，且优良特性稳定。该菌株生产的啤酒口感良好，现已投入啤酒酿造生产。 用紫外线和甲基磺酸乙...Brewer’s yeast strain is the key to the beer brewage production. So it is an important task to select an excellent yeast strain. In the study, physical and chemical mutagenesis and protoplast fusion technique were used to select strains with low-yielding diacetyl, acetaldehyde, total higher alcohols and other excellent characteristics. The strain JY2-2 with excellent fermentation characteristics ...学位：理学硕士院系专业：生命科学学院生物学系_微生物学学号：20042604

Screening of the Fine Brewer′s Yeast Strain JW1-3 and Its Pilot Fermentation

啤酒酵母菌种的优劣在啤酒酿造生产中起着至关重要的作用.为了获得优良的啤酒酿造酵母菌株,试验用半导体激光诱变处理啤酒酵母(Saccharomyces cerevisiae)菌株XB05,在含双乙酰的麦芽汁琼脂平板上分离抗双乙酰的突变株,然后用三角瓶在低温下发酵,以发酵液的发酵度、双乙酰、乙醛和总高级醇的含量为筛选指标,结果得到一株发酵特性优良的菌株JW1-3.菌株JW1-3以9°Bx麦芽汁为培养基,用500 L发酵罐在12℃下发酵13 d,发酵液的发酵度为67.8%,发酵液中的双乙酰、乙醛和总高级醇的含量分别为0.039 4、4.81和60.2 mg/L.菌株JW1-3的主要发酵特性优良且稳定,啤酒口感良好.该菌株在啤酒生产中具有很好的应用前景.Beer is one of the most popular drink at present,and the yeast strain plays a key role on the beer brewing.In order to obtain the fine brewer′s yeast strain,Saccharomyces cerevisiae strain XB05 was radiated by semiconductor laser(wavelength:630 nm;power:1 w) for 10,20 and 30 min.The mono-colonies growing on wort plate agar containing diacetyl 135 μg/mL were isolated.The anti-diacetyl mutants were fermented in 500 mL flask with 300 mL wort at 12℃ for 8 d and selected with the fermented degree and the content of diacetyl,acetaldehyde and total higher alcohols of the fermented liquid as the main target.As a result,the fine strain JW1-3 was obtained.Under the conditions of 500 L fermentor with 400 L 9°Bx wort at 12℃ for 13 d,the fermented degree of mutant JW1-3 was 67.8%,the content of diacetyl,acetaldehyde and total higher alcohols in the fermented liquid were 0.039 4,4.81 and 60.2 mg/L,respectively.The fermented properties of the mutant JW1-3 were relatively stable.The sensory evaluation of the beer produced by the mutant strain JW1-3 was nice.Strain JW1-3 is of well applied prospect on the beer brewing.福建雪津啤酒有限公司资

Screening of the Brewer′s Yeast Strain JY2-2 by Laser Mutagenesis and Its Pilot Fermentation

用He-Ne激光辐照诱变啤酒酵母(Saccharomyces cerevisiae)XB05,分离抗双乙酰的菌株,通过三角瓶发酵筛选,得到几株优良的菌株,其中菌株JY2-2用500 mL三角瓶装300 mL 12.5°Bx麦芽汁在12℃下发酵8 d,发酵液的发酵度为66%,双乙酰、乙醛和总高级醇的含量分别为0.079 0、7.43和87.22 mg/L.以12°Bx麦芽汁为培养基用500 L发酵罐发酵,发酵7 d发酵液的发酵度为68.8%,双乙酰、乙醛和总高级醇的含量分别为0.034 4、5.12和70.6 mg/L.啤酒口感纯正清爽,突变株JY2-2的主要发酵特性稳定,具有很好的应用前景.Several fine brewer′s yeast strains were obtained from the original strain XB05 after mutagenesis with laser and screening.Among the mutants,fermented degree of mutant JY2-2 was 66%,the content of diacetyl,acetaldehyde and total higher alcohols were respectively 0.079 0,7.43,87.22 mg/L under the fermentation conditions of 500 mL flask with 300 mL 12.5°Bx wort at 12℃ for 8 days.The fermentation degree of mutant JY2-2 was 68.8%,the content of diacetyl,acetaldehyde and total higher alcohols in the fermented liquid were respectively 0.034 4,70.6,5.12 mg/L under the conditions of 500 L fermentor with 400L 12°Bx wort at 12℃ for 7 days.The sensory evaluation of the beer produced by the mutant strain JY2-2 was nice.The fermentated properties of the mutant JY2-2 were relatively stable.JY2-2 is of well applied prospect on the beer brewing.福建雪津啤酒有限公司资

Pilot Beer Brewing Test of Protoplast Fusant HN31-6 of Saccharomyces cerevisiae

为了考察啤酒酵母融合株HN31-6的啤酒酿造生产性能,以12.5°Bx麦芽汁为培养基,用500 L发酵罐在12℃下发酵,发酵期间每天取样测定发酵液的发酵度和酒精度以及发酵液的双乙酰、乙醛、高级醇和酯类等挥发性物质的含量.结果表明:在上述条件下,发酵14 d,发酵液的发酵度和酒精度分别为69.9%和4.46%;双乙酰和乙醛的含量分别为0.036 4 mg/L和4.53 mg/L;异戊醇、异丁醇和正丙醇的含量分别为46.47、8.34和9.82 mg/L,总高级醇的含量为64.6mg/L;甲酸乙酯、乙酸乙酯、乙酸异丁酯、乙酸异戊酯和己酸乙酯的含量分别为0.132、21.92、0.037、2.22和0.293 mg/L,总酯为24.6 mg/L;该菌株的发酵度以及发酵液的酒精、双乙酰、乙醛、总高级醇和一些酯类等的含量均达到国家优质啤酒的标准,啤酒口感良好.该融合株在啤酒酿造生产中具有很好的应用前景.In order to inspect the characters of beer brewing of protoplast fusant HN31-6 of Saccharomyces cerevisiae,the fermentation test was carried out under the conditions of 500 L fermentor with 400 L 12.5° Bx wort as the medium at 12℃ for 14 days.The fermentative degree of the fermented liquid and the contents of diacetyl etc volatility substances were analyzed during the fermentation.The results showed that the fermentative degree and alcohol degree of the fermented liquid of fusant HN31-6 under the above-mentioned conditions were 69.9% and 4.46%,respectively.The contents of diacetyl and acetaldehyde in the fermented liquid were(0.036 4) mg/L and 4.53 mg/L,respectively.The contents of isopentitol,isobutylalcohol and n-propyl-alcohol were 46.47,8.34 and 9.82 mg/L,respectively,and the content of total higher alcohols was 64.6 mg/L in the fermented liquid.The contents of methylacetate,ethyl acetate,isobutylacetate,isoamylacetate and ethylcaproate were 0.132,21.92,0.037,2.22 and 0.293 mg/L,respectively;and total ester was 24.6 mg/L.The fermentative degree of the fermented liquid and contents of diacetyl,acetaldehyde and total higher alcohols and some esters in the fermented liquid all achieved the standards of high quality beer.The sensory evaluation of the beer produced by fusant HN31-6 was nice.The fusant HN31-6 has a good prospect in the application for the beer brewing福建雪津啤酒有限公司资

Construction of the Fine Brewer's Yeast Strains DR9-2 by Fusion of Two Inactivated Parents' Protoplast and Study of its Fermentation Characters

啤酒酵母菌株JW1-1发酵液中的双乙酰、总高级醇的含量较低,但发酵度较低,发酵液中的乙醛含量较高;啤酒酵母菌株NW7-45发酵度较高,发酵液中的乙醛含量较低,但发酵液中的双乙酰、总高级醇的含量较高。为了得到优良的菌株,以紫外线灭活的菌株JW1-1原生质体和热灭活的菌株NW7-45原生质体为亲本进行融合。经三角瓶发酵筛选,得到较优良的融合株DR9-2和DR9-24。其中融合株DR9-2以12°Bx麦芽汁为培养基,用500L的发酵罐在12℃下发酵,发酵11d发酵液的发酵度为69.5%,发酵液中的双乙酰、乙醛和总高级醇的含量分别为0.0124mg/L、7.70mg/L和61.88mg/L。从融合株DR9-2的主要发酵特性和啤酒口感品评的结果表明,该菌株在啤酒酿造工业中具有应用前景。Sacchararomyces cerevisiae JW1-1 was a strain with the relatively low content of diacetyl and total higher alcohols but relatively high content of acetaldehyde in the fermented liquid and relatively low fermented degree, while Sacchararomyces cerevisiae NW7-45 was a strain with relatively high fermented degree and relatively low content of acetaldehyde but relatively high content of diacetyl and total higher alcohols in the fermented liquid. .In order to construct the fine brewer's yeast strains, the fusion of UV-inactivated strain JW1-1 protoplast and heat-inactivated strain NW7-45 protoplast was carried out. The fine fusants DR9-2 was obtained after selecting by flask fermentation. The content of diacetyl, acetaldehyde, total high alcohols of DR9-2 in the fermented liquid were 0.0124mg/L,7.70mg/L and 61.88mg/L, respectively, and the fermentation degree was 69.5% in 500L fermentor using 12°Bx wort as the medium at 12℃ for 11 days. The main fermentative property and the sensory evaluation of the beer of DR9-2 indicated that strain DR9-2 is of well applied prospect on the beer brewing

Effects of soil surface mulching on the growth and physiological characteristics of grafted and non-grafted cucumbers in solar greenhouse.

研究了地表覆盖秸秆、地膜和秸秆加膜对日光温室嫁接和非嫁接黄瓜生长与生理特性的影响.结果表明,地表覆盖可有效促进植株生长,嫁接黄瓜覆盖秸秆加膜、地膜与秸秆的株高和茎粗依次比对照增加91、71、57cm和0·127、0·086、0·111cm,非嫁接黄瓜增幅较小;地表覆盖可增强光合作用,嫁接黄瓜覆盖秸秆加膜、地膜、秸秆的净光合速率分别比对照增加2·63、2·08与1·36μmol·m-2·s-1,非嫁接黄瓜增幅较小;嫁接黄瓜覆盖秸秆加膜和秸秆的叶绿素含量比对照增加1·8%和3·15%,而覆盖地膜的叶绿素含量降低了3·8%,非嫁接黄瓜的叶绿素含量变幅较小;嫁接黄瓜覆盖秸秆加膜、地膜、秸秆的根系活力比对照提高0·98、0·48和0·8mgTTC·g-1FW,同一处理的非嫁接黄瓜根系活力增幅较小;地表覆盖可增加单株干物重,提高早期产量和总产量,嫁接黄瓜覆盖秸秆加膜、地膜与秸秆的单株产量比非嫁接黄瓜分别增加16%、5·3%和3·4%