Single-cell oil production by Mortierella isabellina DSM 1414 using different sugars as carbon source

Pure carbon sources, especially carbohydrates which are raw materials deriving from agro-industrial processes, are often used for small-scale single-cell oil production by fermentation. The aim of this study was to investigate the effects of different pure carbon sources on cell growth, lipid accumulation, and γ-linolenic acid (GLA) production by the filamentous fungus Mortierella isabellina DSM 1414 (Deutsche Sammlung von Mikroorganismen). The sugars utilized in this study are found extensively and abundantly in nature, especially in food raw materials and, in consequence, in agro-food industry wastes or surpluses. Thus, the potential of many waste materials containing these sugars to be used in the production of single-cell oil by fermentation could also be evaluated. The effects of the sugars utilized on cell growth, biomass production, and lipid production were investigated. Fatty acids were also analysed in the lipids produced at the end of the fermentations. Results showed that the maximum biomass production was 10.80 g/L in lactose-based media, while the maximum oil production was 5.44 g/L in maltose-based media. Oleic (20.42%–42.94%), palmitic (14.96%–22.19%), and stearic (9.00%–26.92%) acids were the major fatty acids along with linoleic acid (11.35%–18.67%) and GLA (3.56%–8.04%). The production of GLA as the target fatty acid was remarkable. This study indicates that agro-industrial waste including most of the sugars utilized (except for arabinose and sucrose with lipid production of 0.81 and 0.28 g/L, respectively) can be employed for production of single-cell oil by M. isabellina DSM 1414 which contains a high amount of GLA.     

高纯度鼠尾草酸对葵花籽油脂质氧化的保护作用(英文)

从迷迭香干叶子中分离出了高纯度的鼠尾草酸,其纯度高达98.3%。研究了将其添加到葵花籽油中,在加速贮存条件下,对葵花籽油脂质氧化的保护作用。添加了三种不同浓度的鼠尾草酸,包括100mg/kg(CA-100),200mg/kg(CA-200)和300mg/kg(CA-300),同时添加了200mg/kg的BHT作为阳性对照。通过定期测定其各项参数包括过氧化值、硫代巴比妥酸值、游离脂肪酸含量及茴香胺值,来评估鼠尾草酸对葵花籽油脂质氧化的保护作用。结果显示,不同参数得到的结果一致,即随着鼠尾草酸浓度的增加,其对葵花籽油脂质氧化的保护作用显著增强,并且显示出了比合成抗氧化剂BHT更强的抗氧化活性。     

Influence of essential oil of Hyssopus officinalis on the chemical composition of the walls of Aspergillus fumigatus (Fresenius)

The cell walls of the growing hyphae of Aspergillus fumigatus (Fresenius) cultured in the presence or absence of the essential oil of Hyssopus officinalis were isolated and their chemical composition analysed. The presence of the essential oil led to a reduction in levels of neutral sugars, uronic acid and proteins, whereas amino sugars, lipids and phosphorus levels were increased. HPLC analysis of the neutral sugars showed that they consisted mainly of glucose, mannose and galactose, while the amino sugars consisted of glucosamine and galactosamine. The presence of the essential oil in the culture medium induced marked changes in the content of galactose and galactosamine. Cell walls were fractionated by treatment with alkali and acid. The essential oil induced similar alterations in the various fractions with a more marked effect on the major constituents. The alterations were related to changes in the structure of the cells. This revised version was published online in August 2006 with corrections to the Cover Date.     

Conjugated linoleic acid producing potential of lactobacilli isolated from the rumen of cattle

Lactobacilli isolated from the rumen of cattle were subjected to morphological and biochemical characterizations followed by PCR-based identification. Among isolates, Lactobacillus brevis was found to be the most prevalent species in the rumen. For in vitro conjugated linoleic acid (CLA) production, the two isolates of L. brevis and one each of Lactobacillus viridescens and Lactobacillus lactis were selected. The sunflower oil (i.e., 0.25, 0.5 and 1.0%; a rich source of linoleic acid) was added to skim milk as a substrate for CLA production by isolates at 37 °C/12 h. L. brevis 02 was found to be the most potential CLA producer (10.53 mg CLA/g fat) at 0.25% concentration of sunflower oil followed by L. brevis 01 (8.27 mg CLA/g fat). However, at higher level of sunflower oil (i.e., 1.0%), L. lactis was the highest CLA producer (9.22 mg/g fat) when compared to L. brevis and L. viridescens. The results indicated that L. brevis and/or CLA production was inhibited with increasing concentration of sunflower oil in skim milk. In contrast, L. lactis and L. viridescens could tolerate the increasing concentrations of sunflower oil and produced higher CLA. Overall, L. brevis extends a possibility to be used as a direct-fed microbial for ruminants to increase the CLA content in milk, however, in vivo trials are needed for validation of results obtained.     

Production of trans C18:1 and conjugated linoleic acid in continuous culture fermenters fed diets containing fish oil and sunflower oil with decreasing levels of forage

Previously, feeding fish oil (FO) and sunflower seeds to dairy cows resulted in the greatest increases in the concentrations of vaccenic acid (VA, t11 C18:1) and conjugated linoleic acid (CLA) in milk fat. The objective of this study was to evaluate the effects of forage level in diets containing FO and sunflower oil (SFO) on the production of trans C18:1 and CLA by mixed ruminal microbes. A dual-flow continuous culture system consisting of three fermenters was used in a 3 × 3 Latin-square design. Treatments consisted of (1) 75:25 forage:concentrate (HF); (2) 50:50 forage:concentrate (MF); and (3) 25:75 forage:concentrate (LF). FO and SFO were added to each diet at 1 and 2 g/100 g dry matter (DM), respectively. The forage source was alfalfa pellets. During 10-day incubations, fermenters were fed treatment diets three times daily (140 g/day, divided equally between three feedings) as TMR diet. Effluents from the last 3 days of incubation were collected and composited for analysis. The concentration of trans C18:1 (17.20, 26.60, and 36.08 mg/g DM overflow for HF, MF, and LF treatments, respectively) increased while CLA (2.53, 2.35, and 0.81 mg/g DM overflow) decreased in a linear manner (P < 0.05) as dietary forage level decreased. As dietary forage levels decreased, the concentrations of t10 C18:1 (0.0, 10.5, 33.5 mg/g DM) in effluent increased ( P < 0.05) and t10c12 CLA (0.08, 0.12, 0.35 mg/g DM) tended to increases (P < 0.09) linearly. The concentrations of VA (14.7, 13.9, 0.0 mg/g DM) and c9t11 CLA (1.78, 1.52, 0.03 mg/g DM) in effluent decreased in a linear manner ( P < 0.05) as dietary forage levels decreased. Decreasing dietary forage levels resulted in t10 C18:1 and t10c12 CLA replacing VA and c9t11 CLA, respectively, in fermenters fed FO and SFO.     

Lipases in the storage tissues of peanut and other oil seeds during germination

The castor-bean endosperm-the best-studied material of reserve lipid hydrolysis in seed germination-was previously shown to have an acid lipase and an alkaline lipase having reciprocal patterns of development during germination. We studied oil seeds from 7 species, namely castor bean (Ricinus communis L.), peanut (Arachis hypogaea L.), sunflower (Helianthus annus L.), cucumber (Cucumis sativus L.), cotton (Gossypisum hirsutum L.), corn (Zea mays. L.) and tomato (Lycopersicon esculentum Mill.). The storage tissues of all these oil seeds except castor bean contained only alkaline lipase activity which increased drastically during germination. The pattern of acid and alkaline lipases in castor bean does not seem to be common in other oil seeds. The alkaline lipase of peanut cotyledons was chosen for further study. On sucrose gradient centrifugation of cotyledon homogenate from 3-d-old seedlings, about 60% of the activity of the enzyme was found to be associated with the glyoxysomes, 15% with the mitochondria, and 25% with a membrane fraction at a density of 1.12 g cm^-3. The glyoxysomal lipase was associated with the organelle membrane, and hydrolyzed only monoglyceride whereas the mitochondrial and membrane-fraction enzymes degraded mono-, di- and triglycerides equally well. Thus, although the lipase in the glyoxysomes had the highest activity, it had to cooperate with lipases in other cellular compartments for the complete hydrolysis of reserve triglycerides.     

Polyhydroxyalkanoate production using waste vegetable oil and filtered digestate liquor of chicken manure

Abstract

The production of polyhydroxyalkanoates (PHA) using digestate of chicken manure combined with waste sunflower oil as no-cost feedstocks in a multi-stage process was investigated. Using Cupriavidus necator H16 in combined culture media, a maximum PHA accumulation of 4.6?±?0.2?g/L at 75.1?±?1.4% of cell dry matter and a residual cell matter yield of 1.5?±?0.1?g/L were obtained after 96?hr of cultivation (30?°C, 160?rpm, pH 7.0) in flask-based experiments. Manure was acidogenically fermented in a continuous stirring tank reactor in fed-batch mode. The bioreactor was operated at varying organic loading rates (OLR) and hydraulic retention times (HRT) ranging from 1–4?g volatile solids (VS)/L/d and 4–8?days, respectively. Optimal operation was observed at an OLR of 4?g VS/L/d and an HRT of 4?days. Analysis showed the presence of significant amounts of ammonia, potassium, magnesium, calcium, and trace elements, i.e. Fe, Cu, Ni, Mn, Co, Zn, Cr in the digestate. The micro-filtered digestate was utilized as a complex culture media base while waste oil served as an additional carbon source and supplemented for effective PHA production. The total volatile fatty acid content of digestate greatly affected the growth performance of the PHA-producing microorganism Cupriavidus necator H16.     

银杏种子生长特性及其生理变化的研究

从纵径、横径、体积、重量等方面分析了银杏种子的生长特性及其生长过程中水分、糖类物质、脂肪酸、氨基酸的生理变化.结果表明,银杏种子的生长过程曲线为典型的单“S”型,种子纵径、横径、体积、重量、绝对含水量随生长过程呈“S”形变化.各种生理物质含量随种子生长过程呈规律性变化,且各有其特点.其中在种子生长后期糖类物质总量表现出上升的趋势,表明它们是种子中主要的营养储存物质.成熟种子含淀粉8.4%、葡萄糖6.7%、果糖4.2%、多糖0.02%、二糖0.01%;含肉豆蔻酸10.6%、棕榈烯酸4.1%、亚麻酸2.4%、硬脂酸1.9%、油酸1.1%、亚油酸0.4%.银杏种子富含15种氨基酸,成熟种子中总含量为1.56g·100g^-1FW,其中以赖氨酸、天门冬氨酸、丙氨酸、精氨酸、组氨酸、谷氨酸、异亮氨酸的含量较高,它们的含量依次为0.287%、0.163%、0.136%、0.133%、0.123%、0.115%、0.095%.     

Spatial distribution of oil in groundnut and sunflower seeds by nuclear magnetic resonance imaging

Abstract. The nuclear magnetic resonance imaging technique has been used to obtain images of different transverse and vertical sections in groundnut and sunflower seeds. Separate images have been obtained for oil and water components in the seeds. The spatial distribution of oil and water inside the seed has been obtained from the detailed analysis of the images. In the immature groundnut seeds obtained commercially, complementary oil and water distributions have been observed. Attempts have been made to explain these results.     

Glycolytic enzymatic activities in developing seeds involved in the differences between standard and low oil content sunflowers (Helianthus annuus L.)

As opposed to other oilseeds, developing sunflower seeds do not accumulate starch initially. They rely on the sucrose that comes from the mother plant to synthesise lipid precursors. Glycolysis is the principal source of carbon skeletons and reducing power for lipid biosynthesis. In this work, glycolytic initial metabolites and enzyme activities from developing seed of two different sunflower lines, of high and low oil content, were compared during storage lipid synthesis. These two lines showed different kinetic lipid accumulation in the developing embryos. Fatty acids levels during the initial and final stage of lipid synthesis were higher in CAS-6 than in ZEN-8. The analysis of the photosynthate and sugars content suggests that, although the hexoses levels were quite similar in both lines, the amount of sucrose produced by the mother plant and available for lipid synthesis was higher in CAS-6. Although, a smaller amount of sucrose is available in the ZEN-8 line, its seeds maintain the levels of intermediate sugars in the initial steps of glycolysis due to an increase in the levels of the invertase, hexokinase and phosphoglucose isomerase activities in ZEN-8, with respect to CAS-6. Also, a readjustment in the final part of this metabolic route took place, with the activities of phosphoglycerate kinase and enolase in CAS-6 being higher, allowing increased synthesis of phosphoenolpiruvate, the intermediate carbon donor for fatty acid synthesis. In addition, recently, it has been shown that Arabidopsis mutants with a lower fat content in their seeds have a higher amount of sucrose. These data together point to these last two enzymatic activities, phosphoglycerate kinase and enolase, as being responsible for the lower fat content in the ZEN-8 line.     

Use of elephant grass (Pennisetum purpureum) acid hydrolysate for microbial oil production by Trichosporon cutaneum

Elephant grass (Pennisetum purpureum) dilute acid hydrolysate contains 34.6?g/L total sugars. The potential of lipid production by oleaginous yeast Trichosporon cutaneum grown on elephant grass acid hydrolysate was investigated for the first time. During the fermentation process on the elephant grass acid hydrolysate, glucose, xylose, and arabinose could be well utilized as carbon sources by T. cutaneum. Interestingly, xylose was almost no use before glucose was consumed completely. This illustrated that simultaneous saccharification of xylose and glucose by T. cutaneum did not occur on elephant grass acid hydrolysate. The highest biomass, lipid content, lipid yield, and lipid coefficient of T. cutaneum were measured after the sixth day of fermentation and were 22.76?g/L, 24.0%, 5.46?g/L, and 16.1%, respectively. Therefore, elephant grass is a promising raw material for microbial oil production by T. cutaneum.     

发酵性丝孢酵母HWZ004利用水稻秸秆水解液发酵产油脂

为高效利用水稻秸秆中的纤维素和半纤维素产油脂,采用稀酸预处理和酶水解两步法对水稻秸秆进行水解,然后以水解液为碳源,培养发酵性丝孢酵母Trichosporon fermentans HWZ004产微生物油脂。结果表明,经简单overliming法脱毒后水稻秸秆水解液中乙酸、糠醛和5-羟甲基糠醛的浓度分别为0.4 g/L、0.1 g/L和0.05 g/L。只需添加少量氮源和微量CuSO4?5H2O,该水解液即可满足T. fermentans HWZ004发酵产油脂的要求。发酵最适接种量、初始pH和温度分别是5.0％、7.0和25 ℃。T. fermentans HWZ004在优化条件下培养7 d的生物量、油脂含量和油脂产量分别是26.4 g/L,52.2％和13.8 g/L;油脂得率系数为17.0,大大高于驯化前菌株T. fermentans CICC 1368在脱毒水稻秸秆半纤维素水解液中的对应值 (11.9)。所产油脂的脂肪酸组成与植物油相似,不饱和脂肪酸含量达70％以上,宜作为生物柴油的生产原料。     

播娘蒿种子脂肪油组分的GC-MS分析

播娘蒿[Descurainia sophia（L．）Webb ex Prantl]为十字花科（Cruciferae）播娘蒿属（Descuainia Webb et Berth）1～2年生草本植物,其成熟的种子俗称南葶苈子,为临床常用中药材。葶苈子味辛、苦、大寒,具泻肺降气、祛痰平喘、行水消肿之功效。用于痰涎壅肺、喘咳痰多、胸肋胀满、胸腹水肿、小便不利、肺原性心脏病水肿等症。     

江西迷迭香精油的成分分析及抗氧化、抑菌活性研究

为了研究江西迷迭香精油的化学成分及抗氧化、抑菌活性,采用水蒸气蒸馏法提取迷迭香精油,利用气相色谱-质谱联用法(GC-MS)对迷迭香精油成分进行分析,通过对DPPH自由基、羟基自由基的清除活性和还原力来研究迷迭香精油的体外抗氧化活性;通过以枯草芽孢杆菌、金黄色葡萄球菌和大肠杆菌为供试菌,测定抑菌圈大小和最低抑菌浓度(MIC)来研究迷迭香精油的抑菌活性。实验结果表明,从迷迭香精油中鉴定出40种化学成分,占精油总量的99.46%,其主要化学成分有α-蒎烯(39.05%)和1,8-桉叶素(16.86%),其次是莰烯(4.22%)、D-柠檬烯(3.87%)、龙脑(3.74%)、β-石竹烯(3.11%)等,α-蒎烯的含量高于国内其他产地;迷迭香精油对DPPH、羟基自由基和还原力的半数清除率IC₅₀值分别为76.42、51.40和49.15μL/mL;精油对枯草芽孢杆菌、金黄色葡萄球菌和大肠杆菌的抑菌圈大小分别为14.40±0.66、11.41±0.19、11.70±0.27 mm,最低抑菌浓度(MIC)分别为2.50、10.00、10.00μL/mL,对枯草芽孢杆菌的抑制作用明显强于金黄色葡萄球菌和大肠杆菌。结果表明迷迭香精油具有较好的抗氧化、抑菌活性。     

苦橙叶精油化学成分及抗炎作用研究

为探究苦橙叶精油的抗炎作用。实验采用气相-质谱联用法(GC-MS)分析精油成分,并建立脂多糖(LPS)诱导RAW 264.7细胞炎症模型,用Griess法检测一氧化氮(NO)含量评价其体外抗炎作用,随后进一步通过巴豆油致小鼠耳肿胀模型和鸡蛋清致小鼠足肿胀模型评价其体内抗炎作用。结果表明苦橙叶精油成分以酯类、醇类物质为主;25μg/mL浓度能显著抑制RAW 264.7细胞NO的释放;中浓度苦橙叶精油能明显减轻小鼠耳肿胀程度;低、中、高浓度苦橙叶精油均对小鼠足肿胀模型有炎症缓解作用,并于肿胀前期呈浓度依赖性。以上实验证明苦橙叶精油在体外和体内具有一定抗炎作用。     

Chemical constituents and fumigant toxicity of essential oil from Carum copticum against two stored product beetles

Plant secondary metabolites play an important role in plant-insect interactions and therefore such compounds may have insecticidal or antifeedant activity against insects. Carum copticum C. B. Clarke （Apiaceae） is one of these plants that have medicinal effects on humans. The chemical composition of the essential oil from dry seeds of C. copticum was studied by gas chromatography （GC） and gas chromatography mass spectrometry （GC-MS）. Thymol （41.34%）,α-terpinolene （17.46%） and ρ-cymene （11.76%） were found to be the major constituents of the oil. In fumigant toxicity tests with the essential oil against adults of Sitophilus oryzae （L.） and Tribolium castaneum （Herbst） at 27 ±1℃ and 60% ± 5% RH, it was observed that S. oryzae （LC50 = 0.91 μL/L） were significantly susceptible than T. castaneum （LC50 = 33.14 μL/L）. The mortalities of the insect species reached 100% at concentrations higher than 185.2 μL/L and 12-h exposure time. The findings indicate the strong insecticidal activity of C. copticum oil and its potential role as a fumigant for storedproduct insects.     

Molecular basis of the high-palmitic acid trait in sunflower seed oil

Sunflower (Helianthus annuus L.) seed oil with high palmitic acid content has enhanced thermo-oxidative stability, which makes it well suited to high-temperature uses. CAS-5 is a sunflower mutant line that accumulates over 25 % palmitic acid in its seed oil, compared to 5–8 % in conventional cultivars. The objective of this study was to investigate the molecular basis of the high-palmitic acid trait in CAS-5 through both candidate gene and QTL mapping approaches. An F₂ population derived from the cross between CAS-5 and the conventional line HA-89 was developed. A 3-ketoacyl-ACP synthase II (KASII) locus on a telomeric region of linkage group (LG) 9 of the sunflower genetic map was found to co-segregate with palmitic acid content in this population. The KASII locus explained the vast majority of the phenotypic variation (98 %) of the trait. Two minor QTL affecting palmitic acid content were also found on the lower half of LG 9 and on LG 17. Additionally, QTL associated with other major fatty acids (stearic, oleic, and linoleic acid) were identified on LG 1, 6, and 10. This result may reflect untapped genetic variation that could exist among sunflower cultivars for genes determining fatty acid composition. In addition to demonstrating the major role of a KASII locus in the accumulation of high levels of palmitic acid in CAS-5 seeds, this study stressed the importance of characterizing genes with minor effects on fatty acid profile in order to establish optimal breeding strategies for modifying fatty acid composition in sunflower seed oil.     

Acetate enhances citric acid production by Yarrowia lipolytica when grown on sunflower oil

It was discovered that the addition of 10 g/l acetate to a medium containing 30 g/l sunflower oil caused a drastic increase in citric acid production by Yarrowia lipolytica UOFS Y-1701 i.e. from 0.5 g/l in the absence of acetate to 18.7 g/l in the presence of acetate. Similarly, the ratio of citric acid:isocitric acid increased significantly from 1.7:1 in the absence of acetate to 3.7:1 in the presence of acetate after 240 h of growth.     

Isolation and structural characterization of biosurfactant produced by an alkaliphilic bacterium Cronobacter sakazakii isolated from oil contaminated wastewater

Production of biosurfactant from an alkaliphilic bacterium Cronobacter sakazakii (accession no. JN398668) was screened by haemolytic assay, emulsifying activity and surface tension measurement. Biosurfactant, comprised of total sugars (73.3%), reducing sugars (1.464%), protein (11.9%), uronic acid (15.98%) and sulfate (6.015%), showed low viscosity with pseudoplastic rheological behavior and exhibited significant emulsification activity with oils and hydrocarbons. A series of low and mid range mass peaks (m/z) corresponding to mono-, di-, tri- and oligosaccharides were detected in the positive ion reflector mode of MALDI TOF-TOF MS. GC-MS analysis revealed composition of monosaccharide moieties (w/w) viz. glucose (14%), mannose (24%), galactose (14%), xylose (20%) and arabinose (1.9%). ¹H NMR, FT-IR and EDX analyses confirmed the characteristic various functional groups, bonds and elements respectively. Thermostability (up to 260 °C) and CI (0.456) were determined by TG and DSC analyses. Inherent properties of biosurfactant make it a potential candidate for bioremediation of oil and hydrocarbons.     

Extraction and hydrolysis of levoglucosan from pyrolysis oil

Fermentable sugar obtained from lignocellulosic material exhibits great potential as a renewable feedstock for the production of bio-ethanol. One potentially viable source of fermentable sugars is pyrolysis oil, commonly called bio-oil. Depending on the type of lignocellulosic material and the operating conditions used for pyrolysis, bio-oil can contain upwards of 10 wt% of 1,6-anhydro-β-d-glucopyranose (levoglucosan, LG), an anhydrosugar that can be hydrolyzed to glucose. This research investigated the extraction of levoglucosan from pyrolysis oil via phase separation, the acid-hydrolysis of the levoglucosan into glucose, and the subsequent fermentation of this hydrolysate into ethanol.Optimal selection of water-to-oil ratio, temperature and contact time yielded an aqueous phase containing a levoglucosan concentration of up to 87 g/L, a yield of 7.8 wt% of the bio-oil. Hydrolysis conditions of 125 °C, 44 min and 0.5 M H₂SO₄ resulted in a maximum glucose yield of 216% (when based on original levoglucosan), inferring other precursors of glucose were present in the aqueous phase. The aqueous phase contained solutes which inhibited fermentation, however, up to 20% hydrolysate solutions were efficiently fermented (yield = 0.46 g EtOH/g glucose; productivity = 0.55 g/L h) using high yeast inoculums (1 g/L in flask) and micro-aerophilic conditions.