苹果渣基质柠檬酸高产菌株选育

分别以固态苹果渣、苹果渣固态酶解物、苹果渣酶解液和10%葡萄糖溶液为发酵基质研究了17株野生黑曲霉的柠檬酸产生能力,并对获得的4株柠檬酸高产菌进行了诱变育种。结果表明:17株黑曲霉在4种发酵基质中均能良好生长并发酵产生柠檬酸,不同菌株在同一发酵基质中产酸能力间存在差异。FG17、FG23、FG26、FG30等4株菌苹果渣基质柠檬酸产生能力较高,且在4种不同发酵基质中产酸性能稳定。4株菌分别经紫外线和60Co-γ射线诱变后得到的正向突变株柠檬酸产率均显著提高,突变株中FG26-15-4(UV)发酵苹果渣后柠檬酸产率最高,达11.32%,FG23-13-3(γ)发酵苹果渣酶解液后柠檬酸产率最高,达2.73 mg/mL,均高于现有研究报道,可作为不同类型苹果渣基质柠檬酸发酵用菌种。     

黑曲霉固态发酵苹果渣生产木聚糖酶与β-甘露聚糖酶

[目的]采用黑曲霉固态发酵苹果渣生产木聚糖酶与β-甘露聚糖酶,以降低生产成本,同时提高苹果渣的综合利用水平。[方法]采用单因素试验和响应面法对固态发酵工艺进行优化。[结果]培养基最佳组成为苹果渣60%(W/W)、棉粕40%(W/W)、(NH4)2SO41.36%(W/W)、KH2PO40.076%(W/W)、初始含水量55.6%(W/W),最佳培养温度为27.5℃;在所优化的条件下发酵48h,木聚糖酶活力可达5736 U/g,β-甘露聚糖酶活力可达896.24 U/g;培养物中自由棉酚残留量为24.6μg/g,低于饲料中自由棉酚的安全标准。[结论]采用黑曲霉固态发酵苹果渣生产木聚糖酶与β-甘露聚糖酶是可行的,发酵产物可用作饲料添加剂。     

黑曲霉固态发酵苹果渣产β-甘露聚糖酶的工艺优化

目的:对黑曲霉SL-08固态发酵苹果渣生产β-甘露聚糖酶的生产工艺进行优化,旨在探寻苹果渣的综合利用方式,降低β-甘露聚糖酶的生产成本。方法:采用Plackett-Burman试验设计和响应面法进行优化。结果:最佳培养基组成为苹果渣与棉粕1∶1(w/w)、尿素2%(w/w)、KH2PO40.1%(w/w)、初始含水率59%(w/w)、CaCl20.2%(w/w)、MgCl20.1%(w/w),30℃恒温培养48h,β-甘露聚糖酶酶活力可达539U/g干曲,比基础培养基提高了28.3%,达到了以豆粕与麸皮为生产原料时的产酶水平。结论:采用黑曲霉SL-08对苹果渣进行固态发酵是一种有效的生物转化方式,既可用于β-甘露聚糖酶的生产,取代豆粕与麸皮等常规原料,降低生产成本;也可以对苹果渣进行综合利用。     

黑曲霉HG-1发酵苹果渣生产果胶酶的工艺优化及部分酶学性质

目的：采用价格低廉的农业废弃物苹果渣为主要原料生产果胶酶,优化其生产工艺,并对果胶酶的部分酶学性质进行研究。方法：以黑曲霉HG-1为生产菌种,采用单因子实验和正交试验进行固态发酵。结果：最适培养基为苹果渣10g、棉粕10g、（NH4）2SO40.2g、K2HPO40.06g、初始水分含量60%;最适发酵条件为装料量为20g干料/250ml三角瓶,30℃恒温培养48h,果胶酶酶活力可达22248U/g。果胶酶酶促反应最适温度为45℃,最适pH为5.0;在50℃以下,pH3.0～6.0时稳定性良好;Ca^2＋、Mg^2＋、Fe^2＋对该酶有激活作用,而Ba^2＋、Mn^2＋、Zn^2＋有抑制作用。结论：以苹果渣代替麸皮作为黑曲霉HG-1固态发酵生产果胶酶的主要原料在技术上具有可行性,可大幅度降低生产成本;同时还可以部分解决苹果渣的综合利用问题。     

单细胞蛋白生产最佳接种混合比的研究*

以苹果渣混合菌发酵生产单细胞蛋白为例,利用3个和4个菌种分别探讨了多菌种发酵最佳接种混合比的选取问题,获得一种求取最佳接种混合比的有效方法,完善了发酵生产单细胞蛋白这类问题的研究。     

固态发酵生产微生物脂肪酶

脂肪酶在水相和非水相中都具有催化活性,在众多工业领域应用前景十分广阔.但脂肪酶的生产成本仍然过高,限制了其在某些工业领域的大规模使用.固体发酵因具有设备比较简单、能耗低、成本低、对环境危害小、易于推广等诸多优点,已逐渐成为微生物脂肪酶生产的一个重要方式.由于能源成本的抬高和人们环保意识的加强,自上世纪90年代以来,原来一直认为技术含量较低的固态发酵技术重新受到重视并得到了快速的发展.综述了固态发酵在脂肪酶生产中的应用研究,重点介绍了固态发酵生产脂肪酶的特点、脂肪酶固态发酵的影响因素及其生物反应器.     

固态发酵在食品加工中的应用研究进展

固态发酵起源于传统食品生产领域,具有节水、节能、高得率、清洁等优势。现代固态发酵技术在保留传统的基础上突破创新,逐渐拓展应用于现代食品工业多个领域。介绍了食品固态发酵过程的特点、影响因素和规模化装备,综述了固态发酵在食品工业中传统食品、酶制剂、有机酸、食用菌、香料和其他天然活性产物等领域的应用及研究进展,并对固态发酵技术在食品工业中的应用前景进行了展望,为实现食品工业固态发酵规模化绿色制造奠定基础。     

用猕猴桃皮制取柠檬酸

用狲猴桃加工饮料或罐头时,总是先把皮削掉,削掉的皮重量为全果重量的10～16％。如何利用好这一副产品,既涉及到经济问题,也涉及到环境保护问题。柠檬酸是具有一定商业价值的产品,过去通常以蔗糖和糖浆为培养基,采用真菌浸水发酵法制取。近来,有人让黑曲霉菌(Aspergillus niger)在苹果渣上生长,采用固态发酵的方法制取了大量的柠檬酸。所谓固态发酵是指在无液体条件下,让微生物在固体物质上生     

酵母菌和食用真菌混合固态发酵配合蛋白饲料的应用研究

双菌混合发酵是现代发酵技术发展趋势之一,高温酵母菌和担子茵混合固态发酵尝试了一种生产配合饲料的新技术,高温酵母菌生长速度快,适应性强,蛋白含量高;担子菌分解纤维素和半纤维素能力强,利用它们各自特点,经双菌协同混合发酵,不但提高了淀粉渣的蛋白质含量,而且也降低了纤维素和半纤维素含量,从而使无法直接利用的淀粉渣转化为优质配合蛋白饲料。      

固态发酵木薯酒精渣生产生物饲料菌种的筛选

目的:筛选获得能混合固态发酵木薯酒精渣生产生物饲料的真菌组合.方法:利用木薯酒精渣堵养基,初筛能在其上良好生长的植物内生真菌菌株,再将这些菌株两两组合进行固态混菌发酵、添加酵母混菌发酵,测定产物中粗蛋白和粗纤维的含量,获得能有效降低木薯酒精渣中粗纤维、提高粗蛋白含量的菌株组合.结果:菌株G4与C15、Q4与C32混菌发酵效果最好,可将粗蛋白质含最从底物的1.42%分别提高到产物的16.08%与18.54%(于基),粗纤维含量从底物的32.41%降低到27.57%与26.59%.添加酵母培养后,两个组合产物中粗蛋白质含量可进一步提高到21.79%与23.56%,而粗纤维含量几乎无变化.结论:菌株G4(黑曲霉)、C15(白地霉)与郎比可假丝酵母,Q4(黑曲霉)、C32(青霉)与季也蒙假丝酵母可用作混菌固态发酵木薯酒精渣生产生物饲料的菌种.     

Protein enrichment of apple pomace by co-culture of cellulolytic moulds and yeasts

The co-culture of cellulolytic moulds and yeasts on apple pomace in solid-state fermentation (SSF) and liquid-state fermentation (LSF) increased the protein content of apple pomace. The co-culture of Candida utilis and Aspergillus niger was the best among several combinations and increased the protein content of dried and pectin-extracted apple pomace to 20% and 17%, respectively, under SSF conditions.The authors are with the Microbiology Research Laboratory, Department of Biosciences, Himachal Pradesh University, Shimia-171005, India.     

Optimization of production conditions for β-mannanase using apple pomace as raw material in solid-state fermentation

Apple pomace is a wasted resource produced in China in large quantities, disposal of which has caused serious environmental problems. In order to make the best of this residue, apple pomace together with cottonseed powder was used as a raw material to produce β-mannanase in solid-state fermentation (SSF) by Aspergillus niger SN-09. Optimization of fermentation conditions for maximizing β-mannanase production was carried out using Plackett-Burman and Central Composite designs. A mixture of apple pomace and cottonseed powder (3:2, w/w) with 59.2 % (w/w) initial moisture, together with certain ionic compounds and salts, proved to be the optimal medium. The test fungi were inoculated in the optimized medium and incubated at 30°C for 48 h. The activity of β-mannanase reached 561.3 U/g, an increase of 45.7 % compared with that in basal medium, and reached the same level of production as that achieved using wheat bran and soybean meal as raw materials as in most factories in China. This is the first report of the use of apple pomace as a raw material to produce β-mannanase in SSF. This will not only reduce the production cost of β-mannanase, but also represents a new and effective way to make the best use of apple pomace, which can consequently help to reduce the environmental pollution caused by this waste.     

Pineapple waste - a novel substrate for citric acid production by solid-state fermentation

Summary Citric acid production in solid-state fermentation by Aspergillus foetidus ACM3996 was better on pineapple waste than on apple pomace, wheat bran or rice bran. The highest citric acid content achieved on pineapple waste was 16.1 g per 100 g dried pineapple waste, with a moisture content of 70% and in the presence of 3% methanol. This represents a yield of 62.4% based on the sugar consumed.     

Generation of antitumor active neutral medium-sized alpha-glycan in apple vinegar fermentation

The physiologically active substances in apple vinegar have not yet been chemically characterized. We studied the biological functions of apple vinegar produced from crushed apples, and found that the constituent neutral medium-sized alpha-glycan (NMalphaG) acts as an antitumor agent against experimental mouse tumors. NMalphaG is a homoglycan composed of glucose having a molecular weight of about 10,000 and a branched structure bearing alpha (1-4,6) linkages.In this study, we clarified the origin of NMalphaG in apple vinegar by examination of its content in alcohol and acetic acid fermentation products sequentially. We found that NMalphaG appeared in acetic acid fermentation, but not in alcohol fermentation. Furthermore we investigated NMalphaG origin using acetic acid fermentation from alcohol fortifiied apple without alcohol fermentation and from raw material with varying amounts of pomace. The results indicate that NMalphaG originated in the apple fruit body and that its production requires both fermentation processes.     

Immobilization of co-culture of Saccharomyces cerevisiae and Scheffersomyces stipitis in sodium alginate for bioethanol production using hydrolysate of apple pomace under separate hydrolysis and fermentation

Apple pomace as a substrate for bioethanol production is interesting due to its abundance and sustainable availability in varied states like Himachal Pradesh (H.P.), Jammu and Kashmir, Uttarakhand and Arunachal Pradesh, India. In the current study, apple pomace which is the main fruit industrial waste of H.P. was evaluated as feedstock for bioethanol production by the process of enzymatic saccharification using multiple carbohydrases. Microwave pretreatment of the apple pomace resulted in the efficient removal of lignin and crystalline structure of cellulose fibre. The enzymatic saccharification of the pretreated biomass was done by optimizing parameters for maximal saccharification leads to production of 27.50?mg/g of reduce, ng sugar. An enhanced ethanol yield of 44.46?g/l and fermentation efficiency of 58% by immobilized co-culture of Saccharomyces cerevisiae MTCC 3089 and Scheffersomyces stipitis NCIM 3498 under SHF as compared to fermentation performed with free yeast cells, i.e. 34.46?g/l of ethanol and 45% of fermentation efficiency.     

Generation of Antitumor Active Neutral Medium-Sized α-Glycan in Apple Vinegar Fermentation

The physiologically active substances in apple vinegar have not yet been chemically characterized. We studied the biological functions of apple vinegar produced from crushed apples, and found that the constituent neutral medium-sized α-glycan (NMαG) acts as an antitumor agent against experimental mouse tumors. NMαG is a homoglycan composed of glucose having a molecular weight of about 10,000 and a branched structure bearing α (1-4,6) linkages.

In this study, we clarified the origin of NMαG in apple vinegar by examination of its content in alcohol and acetic acid fermentation products sequentially. We found that NMαG appeared in acetic acid fermentation, but not in alcohol fermentation. Furthermore we investigated NMαG origin using acetic acid fermentation from alcohol fortifiied apple without alcohol fermentation and from raw material with varying amounts of pomace. The results indicate that NMαG originated in the apple fruit body and that its production requires both fermentation processes.     

Production of Alcohol from Apple Pomace

Production of ethyl alcohol from apple pomace with a Montrachet strain of Saccharomyces cerevisiae is described. More than 43 g of the ethyl alcohol could be produced per kg of apple pomace fermented at 30°C in 24 h. The fermentation efficiency of this process was approximately 89%.     

Influence of pectinase treatment on fruit spirits from apple mash, juice and pomace

The current investigation was conducted to determine the influence of pectinase treatment on fruit spirits produced from apple mash, juice, and pomace. Crispin apples were processed into apple mash, juice, and pomace in our pilot-plant, and fermented with a commercial Red Star wine yeast (Sachharomyces cerevisiae Davis 904). After fermentation, the samples of fermented apple mash, juice, and pomace were distilled, and the distillates were analyzed by HPLC with a Bio-Rad Aminex HPX 87H column and a refractive index detector. Methanol, ethanol, n-propanol, iso-butanol, and iso-amyl alcohol were identified as the major alcohols in all the apple spirits. Student's t-test results indicate that there are significant differences between the methanol concentrations of pectinase treated and non-pectinase treated apple spirits. Duncan's multiple range tests show significant differences in the concentrations of methanol of the fruit spirits made from apple mash, juice, and pomace. Apple pomace yielded significantly higher methanol concentrations than apple mash and juice. Pectinase treatment had little effect on the concentrations of n-propanol, iso-butanol, and iso-amyl alcohol. It is concluded that fruit spirits made from the pectinase treated mash, juice, and pomace of Crispin apples had methanol concentrations significantly above the United States FDA guidance of 0.35% by volume or 280 mg/100 mL of fruit brandy containing 40% ethanol.     

Solid-state fermentation of grape pomace for ethanol production

Summary Grape pomace was used as a substrate for the production of ethanol under solid-state fermentation conditions. The yield of ethanol amounted to greater than 80% of the theoretical, based on the fermentable sugar consumed.