Influence of fermentation conditions on the surface properties and adhesion of Lactobacillus rhamnosus GG

Background: The surface properties of probiotic bacteria influence to a large extent their interactions within the gut ecosystem. There is limited amount of information on the effect of the production process on the surface properties of probiotic lactobacilli in relation to the mechanisms of their adhesion to the gastrointestinal mucosa. The aim of this work was to investigate the effect of the fermentation pH and temperature on the surface properties and adhesion ability to Caco-2 cells of the probiotic strain Lactobacillus rhamnosus GG. Results: The cells were grown at pH 5, 5.5, 6 (temperature 37 °C) and at pH 6.5 (temperature 25 °C, 30 °C and 37 °C), and their surfaces analysed by X-ray photoelectron spectrometry (XPS), Fourier transform infrared spectroscopy (FT-IR) and gel-based proteomics. The results indicated that for all the fermentation conditions, with the exception of pH 5, a higher nitrogen to carbon ratio and a lower phosphate content was observed at the surface of the bacteria, which resulted in a lower surface hydrophobicity and reduced adhesion levels to Caco-2 cells as compared to the control fermentation (pH 6.5, 37 oC). A number of adhesive proteins, which have been suggested in previous published works to take part in the adhesion of bacteria to the human gastrointestinal tract, were identified by proteomic analysis, with no significant differences between samples however. Conclusions: The temperature and the pH of the fermentation influenced the surface composition, hydrophobicity and the levels of adhesion of L. rhamnosus GG to Caco-2 cells. It was deduced from the data that a protein rich surface reduced the adhesion ability of the cells.

Xylanase production by Aspergillus awamori under solid state fermentation conditions on tomato pomace

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microalgal biomass as a fermentation feedstock for bioethanol production

BACKGROUND The increasing cost of fossil fuels as well as the escalating social and industrial awareness of the environmental impacts associated with the use of fossil fuels has created the need for more sustainable fuel options. Bioethanol, produced from renewable biomass such as sugar and starch materials, is believed to be one of these options, and it is currently being harnessed extensively. However, the utilization of sugar and starch materials as feedstocks for bioethanol production creates a major competition with the food market in terms of land for cultivation, and this makes bioethanol from these sources economically less attractive. RESULT This study explores the suitability of microalgae (Chlorococum sp.) as a substrate for bioethanol production via yeast (Saccharomycesbayanus)under different fermentation conditions. Results show a maximum ethanol concentration of 3.83 g L -1 obtained from 10 g L-1 of lipid-extracted microalgae debris. CONCLUSION This productivity level (∼38% w/w), which is in keeping with that of current production systems endorses microalgae as a promising substrate for bioethanol production.

The osmoadaptive response of the wine yeast Saccharomyces cerevisiae K1-V1116 during icewine fermentation

The adapted metabolic response of commercial wine yeast under prolonged exposure to concentrated solutes present in Icewine juice is not fully understood. Presently, there is no information regarding the transcriptomic changes in gene expression associated with the adaptive stress response ofwine yeast during Icewine fermentation compared to table wine fermentation. To understand how and why wine yeast respond differently at the genomic level and ultimately at the metabolic level during Icewine fermentation, the focus ofthis project was to identify and compare these differences in the wine yeast Saccharomyces cerevisiae KI-Vll16 using cDNA microarray technology during the first five days of fermentation. Significant differences in yeast gene expression patterns between fermentation conditions were correlated to differences in nutrient utilization and metabolite production. Sugar consumption, nitrogen usage and metabolite levels were measured using enzyme assays and HPLC. Also, a small subset of differentially expressed genes was verified using Northern analysis. The high osmotic stress experienced by wine yeast throughout Icewine fermentation elicited changes in cell growth and metabolism correlating to several fermentation difficulties, including reduced biomass accumulation and fermentation rate. Genes associated with carbohydrate and nitrogen transport and metabolism were expressed at lower levels in Icewine juice fermenting cells compared to dilute juice fermenting cells. Osmotic stress, not nutrient availability during Icewine fermentation appears to impede sugar and nitrogen utilization. Previous studies have established that glycerol and acetic acid production are increased in yeast during Icewine fermentation. A gene encoding for a glycerollW symporter (STL1) was found to be highly expressed up to 25-fold in the i Icewine juice condition using microarray and Northern analysis. Active glycerol transport by yeast under hyperosmotic conditions to increase cytosolic glycerol concentration may contribute to reduced cell growth observed in the Icewine juice condition. Additionally, genes encoding for two acetyl CoA synthetase isoforms (ACSl and ACS2) were found to be highly expressed, 19- and II-fold respectively, in dilute juice fermenting cells relative to the Icewine juice condition. Therefore, decreased conversion of acetate to acetyl-CoA may contribute to increased acetic acid production during Icewine fermentation. These results further help to explain the response of wine yeast as they adapt to Icewine juice fermentation. ii

Biocompatible polyhydroxybutyrate (PHB) production by marine Vibrio azureus BTKB33 under submerged fermentation

Polyhydroxybutyrate (PHB) is known to have applications as medical implants and drug delivery carriers and is consequently in high demand. In the present study the possibilities of harnessing potential PHB-producing vibrios from marine sediments as a new source of PHB was investigated since marine environments are underexplored. Screening of polyhydroxyalkanoate (PHA)-producing vibrios from marine sediments was performed using a fluorescent plate assay followed by spectrophotometric analysis of liquid cultures. Out of 828 isolates, Vibrio sp. BTKB33 showed maximum PHA production of 0.21 g/L and PHA content of 193.33 mg/g of CDW. The strain was identified as Vibrio azureus based on phenotypic characterization and partial 16S rDNA sequence analysis. The strain also produced several industrial enzymes: amylase, caseinase, lipase, gelatinase, and DNase. The FTIR analysis of extracted PHA and its comparison with standard PHB indicated that the accumulated PHA is PHB. Bioprocess development studies for enhancing PHA production were carried out under submerged fermentation conditions. Optimal submerged fermentation conditions for enhanced intracellular accumulation of PHA production were found to be 35 °C, pH −7, 1.5 % NaCl concentration, agitation at 120 rpm, 12 h of inoculum age, 2.5 % initial inoculum concentration, and 36 h incubation along with supplementation of magnesium sulphate, glucose, and ammonium chloride. The PHA production after optimization was found to be increased to 0.48 g/L and PHA content to426.88 mg/g of CDW, indicating a 2.28-fold increase in production. Results indicated that V. azureus BTKB33 has potential for industrial production of PHB.

Solid-state fermentation: a continuous process for fungal tannase production

Truly continuous solid-state fermentations with operating times of 2-3 weeks were conducted in a prototype bioreactor for the production of fungal (Penicillium glabrum) tannase from a tannin-containing model substrate. Substantial quantities of the enzyme were synthesized throughout the operating periods and (imperfect) steady-state conditions seemed to be achieved soon after start-up of the fermentations. This demonstrated for the first time the possibility of conducting solid-state fermentations in the continuous mode and with a constant noninoculated feed. The operating variables and fermentation conditions in the bioreactor were sufficiently well predicted for the basic reinoculation concept to succeed. However, an incomplete understanding of the microbial mechanisms, the experimental system, and their interaction indicated the need for more research in this novel area of solid-state fermentation. (C) 2004 Wiley Periodicals, Inc.

Surface activity of surfactin recovered and purified from fermentation broth using a two-step ultrafiltration (UF) process

B. subtilis under certain types of media and fermentation conditions can produce surfactin, a biosurfactant which belongs to the lipopeptide class. Surfactin has exceptional surfactant activity, and exhibits some interesting biological characteristics such as antibacterial activity, antitumoral activity against ascites carcinoma cells, and a hypocholesterolemic activity that inhibits cAMP phosphodiesterase, as well as having anti-HIV properties. A cost effective recovery and purification of surfactin from fermentation broth using a two-step ultrafiltration (UF) process has been developed in order to reduce the cost of surfactin production. In this study, competitive adsorption of surfactin and proteins at the air-water interface was studied using surface pressure measurements. Small volumes of bovine serum albumin (BSA) and β-casein solutions were added to the air-water interface on a Langmuir trough and allowed to stabilise before the addition of surfactin to the subphase. Contrasting interfacial behaviour of proteins was observed with β-casein showing faster initial adsorption compared to BSA. On introduction of surfactin both proteins were displaced but a longer time were taken to displace β-casein. Overall the results showed surfactin were highly surface-active by forming a β-sheet structure at the air-water interface after reaching its critical micelle concentration (CMC) and were effective in removing both protein films, which can be explained following the orogenic mechanism. Results showed that the two-step UF process was effective to achieve high purity and fully functional surfactin.

Rumen fermentation and rumen microbes in Nellore steers receiving diets with different lipid contents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production and characterization of polygalacturonase from thermophilic Thermoascus aurantiacus on submerged fermentation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Very high gravity sucrose fermentation by Brazilian industrial yeast strains: effect of nitrogen supplementation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production of alcoholic beverage from ginger: study of fermentation process and final product quality

Introduction: In Brazil part of the production of ginger is of inadequate quality for export. The production of spirit from felt-over rhizomes is an alternative of great interest to producers of these rhizomes. Aim: Aiming to increase the value of felt-over rhizomes, this work aimed to study the use of ginger as a raw material for alcoholic beverage production. It was evaluated the effect of fermentation conditions on the components of fermented alcoholic, as well as, the quality of alcoholic distilled beverage of ginger. Methods: Dehydrated ginger passed by enzymatic hydrolysis-saccharification processes. The hydrolysate obtained was analyzed for sugar profile in HPLC. The alcoholic fermentation process followed the central composite rotational design for three factors: fermentation temperature (23 to 37ºC), time of fermentation (17 to 33 h) and concentration of inoculum (0.22 to 3.00%). The fermented alcoholic obtained was analyzed in HPLC for the contents of ethanol, methanol, glycerol and residual sugars. The distillated alcoholic beverage of ginger was analyzed for ethanol, methanol, acetaldehyde, ethyl acetate and higher alcohols in the gas chromatography (GC). In addition, copper content and acidity were analyzed Results: Sugar profile of the ginger hydrolysate revealed the presence of 77.8% of glucose. Data analysis of fermentation process showed influence of temperature on ethanol and methanol content of the fermented alcoholic of ginger. Time of fermentation had effect on glycerol content. All parameters of process had influence on residual sugars contents. The HPLC analysis has shown presence of methanol, ethyl acetate, aldehyde, acids, higher alcohols and esters in distilled alcoholic beverage of ginger. Conclusion: Fermented alcoholic of ginger with higher levels of ethanol can be obtained under the conditions of 1.5% w/w of inoculum, 30°C of temperature and 24 hours of fermentation time. In this condition of fermentation process the beverage of ginger had good quality.

重组人甲状旁腺素(rhPTH(1-84))的原核表达及发酵条件初步优化

下载PDF阅读器甲状旁腺激素(Parathyroid Hormone,PTH)是治疗骨质疏松症的药物之一.将人工合成全长人PTH(hPTH(1-84))的核苷酸序列插入pThioHis A载体中,然后转化大肠杆菌(Escherichia coli.),在IPTG的诱导下,成功实现了rhPTH(1-84)的原核表达.通过发酵条件的优化,初步确定1:40接种.LB+30% M9盐溶液的发酵培养基,37℃培养至OD600nm=0.8时,加入终浓度为0.6 mmol/L的IPTG,诱导8 h的较优发酵程序.

己酸乙酯酯化真菌筛选及发酵条件研究

本文主要研究了具有己酸乙酯酯化活性的真菌菌株的筛选和发酵条件优化。从大曲和糟醅样品中分离纯化获得79株产生透明圈的丝状真菌，菌落形态初步识别结果显示分离菌株包括红曲霉属、根霉属及曲霉属等菌株。其中菌株EM-56酯化酶活力最强，发酵获得的粗酶制剂酶活为172.36 u。根据显微形态、菌落形态及生理生化特征，初步鉴定该菌株为曲霉科红曲霉属紫色红曲霉（Monascus purpureus）。 在此基础上重点研究了菌株EM-56在不同培养基成分及不同培养条件下的产酶情况，确定了最佳培养基和培养条件。通过单因素实验确定在基础培养基中添加最佳碳源为葡萄糖，最佳氮源为蛋白胨。正交优化实验结果确定了最佳培养基组成：以麸皮为基础培养基，添加葡萄糖 2%，蛋白胨 0.3 %，KH2PO4.3H2O 0.05 %，MgSO4.7H2O 0.06 %。菌株EM-56在上述培养基中的最佳发酵条件为：初始pH 5.5，发酵温度为35°C，发酵时间7d，种龄48h，接种量8%，装瓶量50g / 瓶（500mL）。在最佳培养基和发酵条件下，菌株EM-56发酵获得的粗酶制剂酶活达到241.56 u，比优化前提高了40.15%。 In this paper, the research focuses on the selection of fungus with esterifying activity and optimization of fermentation conditions. We isolated 79 strains which had transparent zones from Daqu and fermented grains. The isolated strains contained Monascus、Rhizopus and Aspergillus through primary morphology analysis. The strain of EM-56 which produces strongest esterase was selected. The enzyme activity reached 172.36u. According to related literature, EM-56 was identified as Monascus purpureus through morphology analysis and biochemical determination. We also studied the effects of different medium and fermentation conditions on the esterase production of strain EM-56. The optimal medium and fermentation conditions were determined. Single factor experiment result shows that the optimal carbon source added is glucose and the optimal nitrogen source added is peptone. The optimal fermentation medium determined by orthogonal optimization test is as follows: wheat bran as substrate, glucose 2%, peptone 0.3%, KH2PO4.3H2O 0.05%，MgSO4.7H2O 0.06%. The optimal fermentation conditions are: initial pH 5.5, cultural temperature 35°C, cultural time 7d, seed age 48h, inoculation 8%, medium mass 50g / flask（500mL）. The esterse activity of EM-56 cultivated in the optimal medium and fermentation conditions reached 241.56u and increased by 40.15% compared with the original activity.

微生物法生成辅酶Q10的研究

本文根据我们实验室建立的发酵产物中辅酶Q10定性定量检测方法，筛选得到一株可以代谢产生较多辅酶Q10的野生菌株放射形土壤杆菌(Agrobacterium radiobacter No.50)。 为了提高放射形土壤杆菌的辅酶Q10的产量，本实验利用液体培养研究了单因素对菌株辅酶Q10产量的影响，并用正交法确定了最佳液态发酵条件。最佳发酵培养基是：葡萄糖20g,蔗糖40g, 硫酸铵10g,玉米浆30g, 酵母膏3g，K2HPO4 3g,MgSO4.7H2O 1g，蒸馏水1000mL,pH 7.0-7.2。最佳发酵条件是：转接斜面菌种到种子培养基, 转速220r/min、温度28。C培养24h后，转入发酵培养基(250mL三角拼装液量为50mL，pH 7.0), 接种量为10％，转速220r/min、温度28。C，培养120h。在此条件下，菌体湿重约为50g/L，辅酶Q10含量约为20mg/L。 本文以放射形土壤杆菌为出发菌株进行诱变育种，以期获得辅酶Q10高产菌。根据微生物育种原理、参照辅酶Q10的代谢调控机制，以野生型放射形土壤杆菌(Agrobacterium radiobacter No.50)为出发菌株，采用紫外线和亚硝基胍复合诱变技术，依次筛选得到菌体提取物M抗性菌ARM－7、烟草提取物T抗性菌株ARMT-26、Vk3抗性菌株ARMTV-25、链霉素抗性菌株ARMTVS-32，菌株ARMTVS-32产量达到了36.8mg/L，与原始出发菌株相比，产量提高了77％。 研究了茄尼醇、对羟基苯甲酸、橘子皮提取物D、胡萝卜提取物E、烟草提取物对ARMTVS-32合成辅酶Q10的影响，结果表明这些物质对菌体合成辅酶Q10有一定促进作用，添加0.2g/L茄尼醇时，辅酶Q10含量提高了17%，达到了40.7mg/L；添加1.2g/L橘子皮提取物D时，辅酶Q10含量提高了13.8%，达到了39.6mg/L；添加0.5g/L胡萝卜提取物E时，辅酶Q10含量提高了25.3% ，达到了43.6mg/L；添加8g/L烟草提取物时，辅酶Q10含量提高了12.6%，达到了39.2mg/L。 Production of Coenzyme- Q10 (CoQ10) by fermentation is considered as a process with broad prospects.Quantitative Analysis of CoQ10 in the culture of microbe by TLC—UV spectrophotometry was developed, by using this method we got the strain Agrobacterium radiobacter,which was isolated from forest soil of southwest of China. The effect of the single factor on CoQ10-production ability of the strain was examined by liquid cultured, and its best optimum cultivation conditions were established by orthogonal method. The results showed that the optimum fermentation conditions were as following: carbon sources glucose 20g/L,sucrose 40g/L; nitrongen sources (NH4)2SO4 10g/L,maize liquid 30g/L;yeast extract 3g; K2HPO4 3g/L,MgSO4.7H2O 1g/L; initial pH was 7 and volume of medium(medium volume vs flask volume) was 50mL/500mL, incubating for 120h on a rotary shaker at 220 rpm and 28℃.Under these conditions, the biomass and CoQ10 concentration reached 50g/L and 20mg/L respectively. According to the biosynthesis mechanism of CoQ10 and breeding theory, CoQ10 over-production strains were screened by UV--NTG. mutation using Agrobacterium radiobacter No.50 as parent strain. A microbe-juice resistant mutant ARMTVS-32, which also could resist tobacco-juice, VK3 and streptomycin, was screened out from an agar plate. The CoQ10 content of ARMTVS-32 reached 36.8mg/L, which was 77% higher than the initial strain. In addition, We discussed the effects of some organic substrates on the synthesis of CoQ10 in ARMTVS-32. The results showed that solanesol, orange juice D, carrot juice E and tobacco juice could promote the CoQ10 accumulation in the cells. The CoQ10 content of ARMTVS-32 reached 40.7mg/L when added 0.2g/L solanesol,it reached 39.6mg/L when added 1.2g/L orange juice D，it reached 43.6mg/L when added 0.5g/L carrot juice E. it reached 39.2mg/L when added 8g/L tobacco juice.

一株掷孢酵母利用红薯淀粉酶解液积累油脂研究

本论文以红薯淀粉的双酶法水解液为碳源，从19 株红色酵母中筛选出一株油脂含量较高的菌株掷孢酵母（Sporobolomyces reseus）As.2.618。为了提高掷孢酵母（S.reseus）As.2.618 的油脂产量，考察了培养基组成对该菌生长情况及油脂积累的影响。用均匀设计法对培养基组成进行了优化，由DPS软件得出的优化结果为：还原糖103g/L、酵母粉11.5g/L、磷酸二氢钾0.3g/L、硫酸镁0.15g/L。生物量可达19.23 g/L,油脂含量为3.875 g/L。研究了添加二价离子对该菌的生长及油脂积累的影响,结果表明Zn2+对该菌生长和油脂积累都有显著促进作用。研究了发酵条件以及添加氧载体正十二烷对该菌发酵的影响，表明添加正十二烷有利用于该菌生长与油脂积累。得出最佳发酵条件是：在还原糖103g/L、酵母粉11.5g/L、磷酸二氢钾0.3g/L、硫酸镁0.15g/L。添加30mg/L 硫酸锌,接种量为5％，在24h 后添加2g/L 的碳酸钙和2%(v/v)正十二烷，pH6.0 培养温度为27℃，转速为200r/min，培养时间为7 天的条件下，该菌生物量干重可达35.05g/L,油脂含量也达11.98g/L。Lipid is one of the basic material for life-sustaining activities andimportant industrial materials. As lipid resources mainly come from the animal andthe plant, the problem of lipid lack is encountered at times. The lipid frommicroorganisms is the substitute and superior to the above lipid with a short period ofproduction and much cheaper fermentation materials such as agricultural and sidelineproducts or wastes of crop.Thus large scale production and broad application ofmicrobial lipid will be efficient not only in substitute of the animal and the plant lipidfor food and industrial field , but also inducing a new way leading to solve the energyproblem.For the purpose of exploring the characteristics of lipid production of redyeasts from sweet potato starch hydrolysates. 19 red yeasts are screened for thecapability of lipid producing and one strain Sporobolomyces reseus As.2.618 withsuperior performance is sellected.To improve the Sporobolomyces reseus As.2.618’s capability of lipidaccumulation , the components of the medium, which may influence the growth of thestrain and the lipid yield have been studied. To get the optimum mediumcomponents ,the “uniform design” was used .The DPS software gave the optimummedium component is: reducing sugar 103 g/L、yeast extract 11.5 g/L、KH2PO4 0.3g/L、MgSO4 0.15 g/L. The biomass could reach up to 19.23 g/L and lipid yield 3.87g/L with the above composition of fermentation medium.Furthermore the fermentation conditions , addition of the divalent metal ionsand the oxygen vector to increase the strain’s lipid producing capability are tested.The optimum condition is : reducing sugar 103 g/L、yeast extract 11.5 g/L、KH2PO40.3 g/L、MgSO4 0.15 g/L，Adding 30mg/L ZnSO4,and adding 2g/L CaCO3 2％(v/v)n-dodecane after 24h’s fermentation. the optimal fermentation condition were asfollow :30ml medium in the 500ml flask with initial pH 6.0,the flasks with 5%inoculation volume were at 200r/min shaking speed for 7d’s fermentation at27 .Under this kind of condition the high biom ¡æ ass which reach to 35.05 g/L could begot ,the yield of lipid also could reach to 11.98g/L.