Capability of Candidas to Ferment Mixtures of Carbohydrates to Alcohol in Free Cells and Co-Culture

Organic biomass is an attractive feedstock for second generation alcohol production. Wild-type strains of the genus Candida showed capabilities different to produce alcohol fermenting a carbohydrates mixture （synthetic medium）, individually and in co-culture. Therefore, the main objective of this work was to evaluate the capability of Candida wild-type strains isolated from termite gut and rumen liquid, to ferment the most commonly carbohydrates presented in citrus residues, individually and in co-culture to alcohol production. C Tropicalis （LR4） presented higher percentage of carbohydrate consumption （74.20% ± 4.60%）, alcohol production （44.53 ± 0.01 gLl） and maximal alcohol productivity （6.40 ± 0.01 gL-l day） than C Glabrata （T1）. Co-culture schemas, CC1 （LR4： 60%; TI： 40%） and CC3 （first LR4 alone and 2 days later T1） presented the highest alcohol production （45.20 ± 1.30 gL-1 and 46.80 ± 2.60 gL-1, respectively）. Maximal alcohol productivity was obtained with CC2 （LR4： 80%; TI： 20%） and CC3 schemas, 7.70 ± 0.29 gL-1 day and 7.80 ± 0.44 gL-l day, respectively. The results suggest the usefulness of these wild-type strains in co-culture as an alternative to alcohol production from carbohydrates mixtures at concentrations commonly found in citrus waste.

Internal transcribed spacer sequencing to explore the intrinsic composition of fungal communities in fungal esophagitis

BACKGROUND Fungal esophagitis(FE)is caused by fungal invasion of the esophageal mucosa.Under endoscopy,the esophageal mucosa shows edema,congestion,erosion,and ulceration,and bleeds easily when touched,and the surface of the mucosa is covered with small white spots like"bean curd residue".Clinical cases showing typical FE under endoscopic imaging but negative esophageal mucosal brush(referred to as suspected FE)have increased the difficulty and challenge of clinical diagnosis and treatment.At present,the esophageal fungal flora of suspected case has not been thoroughly studied.AIM To characterize the fungal flora in FE,suspected FE,and the esophageal normal controls(NCs),and to identify marker species to improve detection of FE.METHODS This was a case-control study.A total of 19 patients with FE,16 with suspected FE,and 10 NCs were selected by endoscopy.The esophageal cell brush samples of each group were sequenced by internal transcribed spacer(ITS)1 and analyzed by bioinformatics.RESULTS In FE and suspected FE patients,species richness,species diversity and species evenness,as measured by the Chao1 index,Shannon index and Pielou index,were lower than in the NCs,and the comparison between the FE and NCs was the most significant(P<0.05).Compared with the NCs,the relative abundance of Candida in FE and suspected FE patients was significantly increased(P<0.001),while the relative abundance of Yarrowia was significantly decreased(P<0.05).Moreover,Yarrowia abundance in the FE group was significantly lower than in the NCs and suspected FE groups(P<0.001).The area under the curve for Candida in FE and suspected FE patients was 99.5%(P<0.05)and 81.3%(P<0.05),respectively.Finally,compared with FE patients,the relative abundance of Ascomycota and Candida in the esophageal flora of suspected FE patients was decreased,while the relative abundance of Yarrowia,Thermomyces and Pichia was increased.CONCLUSION ITS showed that composition of the fungal community was similar in the FE and suspected FE groups.ITS can be used as an auxiliary diagnostic method for FE and provide a theoretical basis for follow-up diagnosis and treatment.

In vitro antifungal activity againstCandidaspecies of Sri Lankan orthodox black tea (Camellia sinensisL.) belonging to different agro-climatic elevations

Objective:To investigate the antifungal potential of different grades of Sri Lankan orthodox black tea [orange pekoe, broken orange pekoe fannings (BOPF) and Dust No. 1] belonging to the three agro-climatic elevations (low, mid and high). Methods: Antifungal activity was assessedin vitro using methanolic extracts (300μg/disc) and agar disc diffusion bioassay technique against threeCandida species,Candida albicans (C. albicans),Candida glabrata(C. glabrata), andCandida tropicalis. ketoconazole and itraconazole mixture was used as positive control (10μg/disc) and methanol was used as the negative control. The minimum inhibitory concentrations were also determined using standard protocols. Results: None of the extracts were effective againstCandida tropicalis. Furthermore, orange pekoe grade tea belonging to all agro-climatic elevations did not induce any antifungal activity againstC. albicans andC. glabrata as well. Conversely, Dust No. 1 belonging to all three agro-climatic elevations and low-grownBOPF showed moderate antifungal activity againstC. albicans andC. glabrata. Interestingly, the severity of the antifungal effect varied with agro-climatic elevations. The minimum inhibitory concentrations ranged from 64.00–128.00μg/mL againstC. glabrata and 128.00-256.00μg/mL againstC. albicans. Conclusions:Sri Lankan Dust No. 1 andBOPF have marked antifungal activityin vitro and offer promise to be used as a supplementary beverage in prophylaxis and during drug treatment in candidiasis.

Ability of Helicobacter pylori to internalize into Candida

The following are our views regarding the“letter to the editor”(Helicobacter is preserved in yeast vacuoles!Does Koch’s postulates confirm it?)by Alipour and Gaeini,and the response“letter to the editor”(Candida accommodates nonculturable Helicobacter pylori in its vacuole-Koch’s postulates aren’t applicable)by Siavoshi and Saniee.Alipour and Gaeini rejected the methods,results,discussion,and conclusions summarized in a review article by Siavoshi and Saniee.The present article reviews and discusses evidence on the evolutionary adaptation of Helicobacter pylori(H.pylori)to thrive in Candida cell vacuoles and concludes that Candida could act as a Trojan horse,transporting potentially infectious H.pylori into the stomach of humans.

Single-cell transcriptomics reveals T-cell heterogeneity and immunomodulatory role of CD4^(+) T native cells in Candida albicans infection

Objective:Candida albicans is a common fungal pathogen that triggers complex host defense mechanisms,including coordinated innate and adaptive immune responses,to neutralize invading fungi effectively.Exploring the immune microenvironment has the potential to inform the development of therapeutic strategies for fungal infections.Methods:The study analyzed individual immune cell profiles in peripheral blood mononuclear cells from Candida albicans-infected mice and healthy control mice using single-cell transcriptomics,fluorescence quantitative PCR,and Western blotting.We investigated intergroup differences in the dynamics of immune cell subpopulation infiltration,pathway enrichment,and differentiation during Candida albicans infection.Results:Our findings indicate that infiltration of CD4^(+)naive cells,regulatory T(Treg)cells,and Microtubules(MT)-associated cells increased after infection,along with impaired T cell activity.Notably,CD4^(+) T cells and plasma cells were enhanced after infection,suggesting that antibody production is dependent on T cells.In addition,we screened 6 hub genes,transcription factor forkhead box protein 3(Foxp3),cytotoxic T-lymphocyte associated protein 4(CTLA4),Interleukin 2 Receptor Subunit Beta(Il2rb),Cd28,C-C Motif Chemokine Ligand 5(Ccl5),and Cd27 for alterations associated with CD4^(+) T cell differentiation.Conclusions:These results provide a comprehensive immunological landscape of the mechanisms of Candida albicans infection and greatly advance our understanding of adaptive immunity in fungal infections.

Oral candidiasis and potential risk factors among disabled and nondisabled in Al-Baha region, Saudi Arabia

BACKGROUND Oral candidiasis(OC)is an oral health disease that could influence patients’oral health quality of life.AIM To estimate prevalence of OC among disabled and non-disabled individuals and its potential risk factors in the Al-Baha region,Saudi Arabia.METHODS An observational cross-sectional study was carried out among 148 disabled and non-disabled participants.The technique of concentrated oral rinse employing the Sabouraud Dextrose Agar medium accompanied with 0.05%chloramphenicol was conducted to assess and isolate candida.Oral examination using the World Health Organization guidelines was conducted to examine participants’oral hea-lth status.A pre-designed questionnaire was also used to evaluate sociodemo-graphic,medical history,and oral hygiene habits of the studied population.RESULTS Out of 148 participants(n=57,38%)had colonized candida.None of the studied population had visible Candida lesions.However,Candida was found in the oral rinses without the subject presenting any lesions or issues caused by Candida(asymptomatic colonization).The most common prevalent OC among participants were Candida albicans,Candida glabrata,Candida dubliniensis,Candida krusei,Candida tropicalis,and Candida parapsilosis(n=35,61%;n=8,14%;n=6,10%;n=5,9%;n=2,4%;and n=1,2%)respectively.Diabetes,smoking,poor plaque,and gingival status were key potential risk factors that significantly associated with candida’s density and presence(P=0.001,P=0.001,P=0.01,and P=0.01)respectively.Disability status had no statistically significant effect on presence and density of Candida.CONCLUSION The prevalence of OC is almost third of the studied population;thus,may provoke a need to develop preventive strategies to reduce the OC rate and establish solid treatment plans.

Antimicrobial and synergistic effects of lemongrass and geranium essential oils against Streptococcus mutans,Staphylococcus aureus,and Candida spp.

BACKGROUND The oral cavity harbors more than 700 species of bacteria,which play crucial roles in the development of various oral diseases including caries,endodontic infection,periodontal infection,and diverse oral diseases.AIM To investigate the antimicrobial action of Cymbopogon Schoenanthus and Pelargonium graveolens essential oils against Streptococcus mutans,Staphylococcus aureus,Candida albicans,Ca.dubliniensis,and Ca.krusei.METHODS Minimum microbicidal concentration was determined following Clinical and Laboratory Standards Institute documents.The synergistic antimicrobial activity was evaluated using the Broth microdilution checkerboard method,and the antibiofilm activity was evaluated with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay.Data were analyzed by one-way analysis of variance followed by the Tukey post-hoc test(P≤0.05).RESULTS C.schoenanthus and P.graveolens essential oils were as effective as 0.12%chlorhexidine against S.mutans and St.aureus monotypic biofilms after 24 h.After 24 h P.graveolens essential oil at 0.25%was more effective than the nystatin group,and C.schoenanthus essential oil at 0.25%was as effective as the nystatin group.CONCLUSION C.schoenanthus and P.graveolens essential oils are effective against S.mutans,St.aureus,Ca.albicans,Ca.dubliniensis,and Ca.krusei at different concentrations after 5 min and 24 h.

Excipient effect on antimicrobial activity of Cinnamon (Cinnamomum zelylanicum album) oil, Thyme (Thymus vulgaris) oil and Ajowan (Trachyspermum ammi) oil

Background:Many herbal essential oils are potential antimicrobials but their pharmaceutical utility is restricted due to a lack of suitable excipients to mollify their dermatotoxicity and irritant property,and outcome of their therapeutic use may vary with different diluents used.Methods:Effect of 16 diluents(dimethyl sulfoxide,liquid paraffin,glycerine,oils of mustard,sunflower,rice bran,palm,groundnut,olive,coconut,sesame,avocado,jojoba,castor,linseed and soybean)was assessed on antimicrobial activity of 2%cinnamon(Cinnamomum zelylanicum album),thyme(Thymus vulgaris)and ajowan(Trachyspermum ammi)oils using agar well diffusion assay.The effect of excipients was evaluated on six Candida albicans,five Escherichia coli,four Acinetobacter lwoffii,two strains each of Staphylococcus aureus,Enterobacter agglomerans,and Enterococcus faecium and one strain each of Acinetobacter calcoaceticus,Escherichia fergusonii,Klebsiella oxytoca,K.pneumoniae ssp.pneumoniae,Leclercia adecarboxylata,Paenibacillus amylolyticus,Proteus mirabilis,P.vulgaris,Pseudomonas aeruginosa,Raoultella terrigena,Staphylococcus capitis ssp.capitis,S.chromogenes,S.epidermidis,S.warneri and Streptococcus pyogenes.Results:Thyme oil(2%)maintained it antimicrobial activity on dilution in dimethyl sulfoxide and glycerine,and ajowan oil(2%)completely lost its antibacterial activity in all diluents except dimethyl sulfoxide.However,cinnamon oil partially lost its antimicrobial activity upon dilution in glycerine,vegetable,and mineral oils in comparison to dimethyl sulfoxide.Olive oil was the best vegetable oil,almost comparable to dimethyl sulfoxide and castor oil was the worst diluent for maintaining antimicrobial activity of cinnamon oil.Conclusion:The study indicated the non-suitability of vegetable oils for pharmaceutical formulations of essential oils except olive oil for dilution of cinnamon oil and glycerol for thyme oil to replace dimethyl sulfoxide as diluent.

Epidemiology, Clinical Features and Antifungal Resistance Profile of Candida auris in Africa: Systematic Review

Candida auris since it discovery in 2009 is becoming a severe threat to human health due to its very quickly spread, its worldwide high resistance to systemic antifungal drugs. In resource-constrained settings where several conditions are met for its emergence and spread, this worrisome fungus could cause large hospital and/or community-based outbreaks. This review aimed to summarize the available data on C. auris in Africa focusing on its epidemiology and antifungal resistance profile. Major databases were searched for articles on the epidemiology and antifungal resistance profile of C. auris in Africa. Out of 2,521 articles identified 22 met the inclusion criteria. In Africa, nearly 89% of African countries have no published data on C. auris. The prevalence of C. auris in Africa was 8.74%. The case fatality rate of C. auris infection in Africa was 39.46%. The main C. auris risk factors reported in Africa were cardiovascular disease, renal failure, diabetes, HIV, recent intake of antimicrobial drugs, ICU admissions, surgery, hemodialysis, parenteral nutrition and indwelling devices. Four phylogenetic clades were reported in Africa, namely clades I, II, III and IV. Candida auris showed a pan-African very high resistance rate to fluconazole, moderate resistance to amphotericin B, and high susceptibility to echinocandins. Finally, C. auris clade-specific mutations were observed within the ERG2, ERG3, ERG9, ERG11, FKS1, TAC1b and MRR1 genes in Africa. This systematic review showed the presence of C. auris in the African continent and a worrying unavailability of data on this resilient fungus in most African countries.

Treatment of Vulvovaginal Candidiasis with A Strategy Based on Phototherapy (M.A.C.® Scar Acceleration Method)

Candidiasis, also known as candidiasis vulvovaginitis, is an infection caused by different types of Candida fungi, the most frequent being Candida albicans. The present study reports an effective strategy, which opens new avenues for the treatment of this public health problem. The MAC® Methodology, conventional laser light-emitting (LLLT)/LED) methods are based on the biphasic response demonstrated many times in LLLT research and as with other forms of drugs, a “drug” (irradiation parameters) and a “dose” (irradiation times) and the “Arndt-Schulz Law” is often cited as a suitable model to describe the dose-dependent effects of LLLT. This method uses photopharmaceuticals, cell markers and the use of correct parameters for each case to induce the acceleration of tissue repair. The present study shows a case of a 32-year-old patient diagnosed with recurrent candidiasis 4 years ago. Eighteen sessions were performed (every other day) using a photoactivated component (Methylene blue 1% + Clotrimazole 1%) and LED phototherapy (red, blue and violet) with emission times of 60 - 260 seconds for each applicator, according to the dose recommendations of the scar acceleration method (MAC®). At the sixth treatment session there was a noticeable decrease in the itching sensation reported by the patient. In session 11 she reported feeling a great improvement, indicating that she no longer felt itching in any area after 18 sessions. The present case demonstrates new methodologies to treat common problems in the population that have a positive impact on the quality of life. This methodology has a promising future because it is non-invasive and requires a great biological transformation for inflammatory, fungal and viral control.

甲酸脱氢酶在Klebsiella pneumoniae中的表达和功能分析

在甘油厌氧发酵生产1,3-丙二醇的过程中,需要消耗还原当量NADH,NADH的有效供给决定了1,3-丙二醇的产量和得率。采用PCR方法从Candidaboidinii基因组中克隆编码甲酸脱氢酶基因fdh,将fdh基因片段插入载体pMALTM-p2X中,构建表达载体pMALTM-p2X-fdh,并转入1,3-丙二醇生产菌Klebsiella pneumoniae YMU2,获得重组菌Klebsiella pneumoniae F-1。研究了重组质粒的稳定性和IPTG诱导fdh基因过量表达的条件。结果表明,重组质粒具有良好的稳定性;fdh基因表达的蛋白分子量为40.2kDa;IPTG诱导表达研究表明,在IPTG浓度为0.5mmol/L时,诱导4h后甲酸脱氢酶表达明显;发酵过程中甲酸脱氢酶比酶活达到5.47U/mg;与出发菌株K.pneumoniae YMU2相比,重组菌F-1合成1,3-丙二醇的浓度提高了12.5%。

鸡粪中氨氮降解菌的分离鉴定及除氨适宜条件研究

【目的】氨气是畜禽养殖业中最常见、危害最大的有害气体之一。为了获得用于治理畜禽粪便氨气污染的微生物,从发酵3 d的鸡粪中分离筛选高效氨氮降解菌,研究其对鸡粪的除氨效果。【方法】以硫酸铵为唯一氮源,对鸡粪中具有氨氮降解能力的微生物进行连续10代的富集培养,将获得的富集培养液按10-1梯度稀释后进行分离纯化。分离得到的单菌落接种至富集培养基中,培养24h后,测定培养基中剩余的氨氮含量,比较各菌株之间的氨氮降解率,筛选出具有高效氨氮降解能力的菌株。通过形态观察、分子生物学以及生物化学的方法进行菌株鉴定。研究不同温度(20℃、25℃、30℃、35℃、40℃)和p H(3.0、4.0、5.0、6.0、7.0、8.0、9.0)对菌株生长的影响,探索不同碳源(淀粉、甘露醇、柠檬酸钠、葡萄糖、乙酸钠、碳酸氢钠)、C/N(5、10、20、40)以及初始氨氮浓度(100、300、600、1 200mg·L^(-1))对菌株氨氮降解性能的影响。最后将得到的目标菌株制成菌悬液,按10%的接种量接种到鸡粪中,同时以等量无菌生理盐水作为对照组,分别培养24 h、48 h、72 h和96 h,测定鸡粪的氨气散发量以及不同形态氮素的变化情况,评价目标菌株对鸡粪的除氨效果。【结果】通过富集培养,从鸡粪中共分离出15株能够降解氨氮的菌株,进一步筛选得到1株氨氮高效降解菌LSA,经鉴定为克柔假丝酵母(Candida krusei),与Candida krusei isolate EM12(JF274497.1)的相似性达到99%,Gen Bank中的登录号为KT025851。该菌株的对数生长期为6-12h,可在p H 3-7,20-40℃条件下生长,能够分别利用葡萄糖、乙酸钠、淀粉、柠檬酸钠、甘露醇作为碳源,不能利用无机碳,当培养基的C/N为20时氨氮去除效果最佳。随着培养基中初始氨氮浓度的升高,菌株LSA对氨氮的降解率呈现下降趋势;与之相反,氨氮降解速率则随着初始浓度的升高呈现升高趋势。当氨氮初始浓度为327.20mg·L^(-1)时,60h内菌株LSA对氨氮的去除率达到71.88%,菌体含量为OD6002.45;当氨氮初始浓度为1 105.26mg·L^(-1)时,96h内菌株LSA对氨氮的去除率达到57.44%,菌体含量达到OD600 2.96。将其接种到鸡粪中可以显著降低鸡粪中氨氮的含量,最高可降低22.30%;减少粪中氨气的挥发量,最高可降低15.92%;增加粪便总氮含量;降低粪便氨氮占总氮的比重。【结论】克柔假丝酵母(Candida krusei)LSA菌株具有高效氨氮降解能力和较强的环境适应性,可有效减少鸡粪中的氨氮含量,降低氨气的挥发量。

一株酵母菌高温驯化与同步糖化发酵研究

对实验室筛选出的一株耐高温酵母菌Y8(Candida maltosa)进行高温驯化,对驯化后菌株的高温产乙醇特性及同步糖化发酵进行研究。结果表明,与原菌株Y8相比,经驯化的菌株Y8-5(Candida maltosa)在高温条件下的生长发酵能力得到进一步提高。在46℃,4%葡萄糖情况下,其发酵性能均能接近正常发酵温度(30℃)下酵母的发酵水平。46℃、以3%(w/v)玉米秸秆、30PFU/g酶,用该菌株进行同步糖化和发酵,得到13.93g/L的乙醇,达到理论产率的88.2%。菌株Y8-5显示了较好的耐高温性能和乙醇发酵特性,为同步糖化发酵技术生产燃料乙醇提供了高温菌种的应用基础。

高浓度苯酚降解菌Candida tropicalis Z-04的鉴定及其对苯酚降解条件的优化

从降解苯酚的好氧颗粒污泥中筛选出一株苯酚降解菌,该菌株最高可耐受2.0 g/L的苯酚。依据形态特征和内源转录间隔区(ITS)的核酸序列分析,将该菌株鉴定为热带假丝酵母菌(Candida tropicalis),并命名为Candida tropicalis Z-04。采用中心复合设计(CCD)法对Candida tropicalis Z-04降解苯酚的条件进行合理设计,利用Design-Expert软件对试验数据进行分析,考察了各因素及其交互作用对苯酚降解率的影响,并得到苯酚最佳降解条件。结果表明,Candida tropicalis Z-04降解苯酚的最佳条件为:酵母提取物投加量0.41 g/L,苯酚初始质量浓度1.03 g/L,菌种投加量1.43%(体积分数),温度30.04℃。在此条件下苯酚的理论预测降解率可达到最大值99.10%。

土壤弹尾目昆虫Folsomia candida对铜污染的急性毒理初步研究

随着土壤环境重金属污染的加剧，有关重金属污染土壤的风险评估受到关注。对土壤质量评价的方法长期以来集中在检测重金属污染物质在土壤中的浓度及化学形态等方面，而对于重金属、土壤和生物之间的相互作用很少考虑，因而难以全面评估重金属对土壤环境的生态毒性效应。重金属污染土壤的生物评价是对化学评价的有效补充和相互验证。

预处理固定化脂肪酶催化合成生物柴油

探讨了预处理固定化Candida antarctica脂肪酶催化餐饮废油合成生物柴油的过程。将固定化Candida antarctica脂肪酶用叔丁醇处理3h后再用废油浸泡4h,用于催化酯交换反应,酯交换反应速率明显加快。研究发现,固定化Candida antarctica脂肪酶预处理后,过量甲醇对酶的抑制作用仍然存在。采用分步添加甲醇工艺,按总醇油摩尔比3∶1,分别在0、0.5、1.0、1.5、2.0、2.5h等量加入甲醇,反应4h后,体系中甲酯含量达到97.86%,反应效率是未处理固定化酶催化合成生物柴油体系的6倍。固定化酶重复使用仍具有较高活性。

界面活化的溶胶凝胶包埋Candida rugosa脂肪酶催化合成维生素E琥珀酸酯

采用界面活化的溶胶凝胶包埋Candida rugosa脂肪酶(CRL)催化合成了维生素E琥珀酸酯. 考察了影响溶胶凝胶包埋固定化CRL的因素, 获得的最佳固定化条件为: 丙基三甲氧基硅烷/正硅酸四乙酯摩尔比为1/1, 水与硅烷前体摩尔比为15, 酶的添加量为0.5mg/ml, PEG400的添加量为12μl/ml溶胶. 溶胶凝胶包埋的CRL在50℃, 18h后其活性仍然保持了70.58%, 是游离酶的2.6倍,且稳定性得到了明显的改善. 基于CRL的界面特性, 采用五种表面活性剂对其进行界面活化. 结果表明, 采用橄榄油活化的溶胶凝胶包埋的CRL合成维生素E琥珀酸酯的酯化活力最高, 相比原酶和未界面活化的溶胶凝胶包埋酶分别提高了6.7和1.43倍.

表面活性剂包衣的固定化脂肪酶在有机介质中催化酯化反应

以大孔吸附树脂为载体,将来源于Candidarugosa的脂肪酶用吸附法固定化后用谷氨酸双十二烷基酯核糖醇进行包衣,用于在有机溶剂中催化月桂酸和月桂醇的酯化反应。结果表明,AB 8型大孔吸附树脂为最佳载体,最适有机溶剂为异辛烷,酶固定化后再包衣,酶的比活较未包衣前提高了60%—90%。

不同渗透压调节剂对Candida krusei生理代谢的影响

比较了氯化钠、氯化钾、甘露醇存在的高渗环境下克鲁氏假丝酵母(Candida kru-sei)的生理代谢。3种渗透压调节剂对C.krusei生理代谢影响有显著差异。与甘露醇相比,氯化钠和氯化钾对细胞生长的影响更为显著,而氯化钾对细胞的毒性则又小于氯化钠。细胞对糖的消耗速率依次为甘露醇>氯化钾>氯化钠。甘油和海藻糖是C.krusei在高渗环境下的主要相容性溶质。氯化钠和氯化钾对甘油合成的促进作用明显高于甘露醇。在0.6mol/L氯化钠、氯化钾、甘露醇存在时,细胞甘油浓度较对照提高了74%、63%、57%;胞内甘油最大含量也分别达到对照的3.1,2.4和1.8倍。高渗环境下胞内海藻糖含量在发酵前期均有所降低,但发酵后期在0.6mol/L氯化钾和甘露醇存在时海藻糖迅速积累,其含量分别达对照的1.6和1.4倍。

酵母Candida krusei对合成染料的脱色

通过筛选实验,从土壤中新分离到1株对活性艳红K-2BP具有明显脱色效果的酵母菌株Y-G-1,经鉴定为克鲁斯假丝酵母Candida krusei.该菌株对含活性艳红K-2BP起始浓度为200mg/L的培养基,最大脱色率为99%,达到最大脱色率的时间是12 h.克鲁斯假丝酵母的最佳接种量应不低于5%(体积分数),培养基最适pH在4～9之间,氮源(NH4)2SO4浓度不低于0.1%,相对应的碳源葡萄糖浓度不低于0.5%.对脱色机理的研究表明,该菌株对活性艳红K-2BP的去除属于降解脱色.此外,该菌株对另外9种染料(50mg/L)的脱色率在62%～96%之间.其中,对偶氮染料弱酸艳红B、活性黑KN-B和活性红M-3BE的脱色率都达到了90%以上,对三苯甲烷染料(酸性媒介漂蓝B)的脱色率达到了93%.表明克鲁斯假丝酵母在染料废水的处理上可能具有较好地应用潜能.