北冰洋来源广谱抗菌海洋细菌的筛选及发酵条件优化

从北冰洋海域沉积物中分离筛选广谱抗菌海洋细菌,通过形态观察、生理生化试验及分子生物学技术对其进行鉴定,并以白色念珠菌（Candida albicans）为指示菌,抑菌圈直径为响应值,通过单因素及响应面试验对其培养条件进行优化。结果表明,分离筛选出一株具有广谱抗菌性的52号菌株,其对白色念珠菌、金黄色葡萄球菌（Staphylococcus aureus）、铜绿假单胞菌（Pseudomonas aeruginosa）、大肠杆菌（Escherichia coli）、鼠伤寒沙门氏菌（Salmonella typhimurium）、肺炎克雷伯氏菌（Klebsiella pneumoniae）均有一定的抑制作用,该菌株被鉴定为枯草芽孢杆菌（Bacillus subtilis）。52号菌株的最佳培养条件为培养温度36 ℃、培养时间75 h、初始pH值6.5、转速178 r/min。在此最优培养条件下,52号菌株对白色念珠菌的抑菌圈直径为30.23 mm。     

几种细菌和藻类吸附铜、铬重金属离子初步研究

重金属污水的排放会破坏生态环境,并通过食物链危害人体和其他动物。该研究在含高浓度铜和铬离子的液体培养基中分别接入三种细菌：大肠杆菌（Escherichia coli）、枯草芽孢杆菌（Bacillus subtilis）、克雷伯氏菌（Klebsiella sp.）和两种光合藻类：斜生栅藻（Scenedesmus obliquus）、小球藻（Chlorella vulgaris）,通过测定培养前后离子的浓度变化,来了解这些微生物对铜离子、铬离子的吸附能力。结果表明,所用细菌对铜离子和铬离子都有较强的吸附能力,铜离子吸附率最高能达到97.8%,铬离子最高能达到99.31%;而所用藻类对铜离子有很强的吸附能力,最高能达到99.99%,对铬离子的吸附率也很可观,处于95%左右。利用微生物处理重金属污水有着较好的效果,且该方法去除较彻底、费用低,因此拥有广阔的应用前景。     

Controlled release of allyl isothiocyanate from brown algae Laminaria japonica and mesoporous silica MCM-41 for inhibiting food-borne bacteria

Allyl isothiocyanate (AITC), a naturally occurring antimicrobial compound, is an effective inhibitor of various pathogens, but its use in the food industry is limited by its volatility and pungency. The objective of this study was to overcome the volatility of AITC using dried Laminaria japonica and mesoporous silica MCM-41 as its carrier. AITC-loaded L. japonica (raw and deoiled) powder and silica MCM-41 was achieved via vapor adsorption. The study of AITC adsorption and desorption was determined by monitoring sample weight changing with time. AITC presence in L. japonica and MCM-41 samples was confirmed by FTIR spectroscopy. Antimicrobial tests were made against 4 microorganisms: Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella Typhimurium. Controlled release and antimicrobial activity from MCM-41 was always superior to those from raw and deoiled L. japonica.     

八角调味料提取物杀菌作用的研究

报道了八角提取的(莽草酸)对细菌的致死作用,特别是八角提取物对病原菌有明显的杀灭作用。在八角调味料提取物浓度为3%,作用时间90~120min的条件下,对几种病原菌杀菌率最高为81.2%~83.5%。这对杀灭有害病原菌找到了一条新途径,对防止病原菌的传播,维护人类健康有重要意义。     

On the relative significance of bacteria for the distribution of polychlorinated biphenyls in Arctic Ocean surface waters

This study presents the first field observations of polychlorinated biphenyls (PCB) in bacteria in oceanic waters. To contribute to the limited knowledge of what role bacteria play in the dynamics of hydrophobic organic contaminants (HOCs) in surface seawater, PCB concentrations were measured in bacteria (0.2-2 microm) collected at seven stations in the northern Barents Sea marginal ice zone (MIZ) and the central Arctic Ocean. Concentrations of individual PCB congeners in bacteria were 0.5-5 ng/g oc (organic carbon), which was as high as or higher than PCB concentrations in bulk particulate organic carbon (POC, "phytoplankton"; > 0.7 microm). Considering the relative biomasses of phytoplankton and bacteria, the amount of PCB in bacteria was generally 5-20% of that in phytoplankton, but at two stations the bacterial biomass contained more PCBs than the phytoplankton pool. This study further showed that efficient PCB uptake in bacteria may be described by an apparent equilibrium partitioning model with linear regressions between the organic-carbon-normalized partition coefficient and the octanol-water partition coefficient (log K(bact-oc)-log K(ow)).     

Tocopherol content of seaweed and seaweed meal: I.—Analytical methods and distribution of tocopherols in benthic algae

A rapid and reliable method for identification and quantitative determination of algal tocopherols has been developed. The algal tocopherols are separated from each other and from other lipids by circular chromatography on paper which contains aluminium ox de. Based on this method the distribution of tocopherols in brown, red and green seaweeds was investigated. α-Tocopherol was the only tocopherol detectable in all algae except for those belonging to the Fucaceae family, which contained the γ and δ-homologues as well.     

球等鞭金藻海藻油的提取工艺

以乙醚/石油醚为溶剂提取球等鞭金藻海藻油。以料液比、乙醚/石油醚体积比、提取温度和提取时间为影响因素,海藻油得率为考察指标,通过单因素实验和正交实验,确定的最佳提取工艺条件为:料液比1∶15,乙醚/石油醚体积比1∶2,提取温度20℃,提取时间5 h;在此条件下,球等鞭金藻海藻油得率为(40.8±1.1)%。     

Functional properties of carotenoids originating from algae

Carotenoids are isoprenoid molecules which are synthesised de novo by photosynthetic plants, fungi and algae and are responsible for the orange, yellow and some red colours of various fruits and vegetables. Carotenoids are lipophilic compounds, some of which act as provitamins A. These compounds can be divided into xanthophylls and carotenes. Many macroalgae and microalgae are rich in carotenoids, where these compounds aid in the absorption of sunlight. Industrially, these carotenoids are used as food pigments (in dairy products, beverages, etc.), as feed additives, in cosmetics and in pharmaceuticals, especially nowadays when there is an increasing demand by consumers for natural products. Production of carotenoids from algae has many advantages compared to other sources; for example, their production is cheap, easy and environmentally friendly; their extraction is easier, with higher yields, and there is no lack of raw materials or limited seasonal variation. Recently, there has been considerable interest in dietary carotenoids with respect to their antioxidant properties and their ability to reduce the incidence of some chronic diseases where free radicals are involved. Possibly, carotenoids protect cells from oxidative stress by quenching singlet oxygen damage with various mechanisms. Therefore, carotenoids derived from algae could be a leading natural resource in the research for potential functional ingredients. Copyright © 2012 Society of Chemical Industry     

褐藻中岩藻聚糖硫酸酯生物学活性的研究进展

岩藻聚糖硫酸酯主要来源于褐藻,是一种含有硫酸基的水溶性杂多糖。岩藻聚糖硫酸酯在医药、保健品、功能性食品等领域有着广泛的应用,岩藻聚糖硫酸酯结构复杂且硫酸基团的量对其一些生物学活性具有影响,因此本文对岩藻聚糖硫酸酯结构,以及抗氧化活性、抗病毒活性、抗肿瘤活性、α-葡萄糖苷酶的抑制等生物学活性进行了综述。      

褐藻中岩藻聚糖硫酸酯生物学活性的研究进展

岩藻聚糖硫酸酯主要来源于褐藻,是一种含有硫酸基的水溶性杂多糖。岩藻聚糖硫酸酯在医药、保健品、功能性食品等领域有着广泛的应用,岩藻聚糖硫酸酯结构复杂且硫酸基团的量对其一些生物学活性具有影响,因此本文对岩藻聚糖硫酸酯结构,以及抗氧化活性、抗病毒活性、抗肿瘤活性、α-葡萄糖苷酶的抑制等生物学活性进行了综述。     

Solubilisation of calcium and magnesium from the marine red algae Lithothamnion calcareum

Marine minerals are a potential source of calcium and magnesium for nutritional supplementation. This study analysed the solubilisation of calcium and magnesium from the skeletal remains of Lithothamnion calcareum. Scanning electron microscopy analysis demonstrated a nonporous microstructure. Spectrophotometric determination showed that the calcium and magnesium contents were 30.01 and 6.22% (w/w), respectively. Solubilisation of calcium and magnesium was highly pH dependent. The temperature‐dependent solubilisation of calcium fitted the shrinking core model. The apparent activation energy for calcium solubilisation was 28.6 kJ mol^?1. Inclusion of caseinophosphopeptides (CPPs), casein‐derived mineral binding peptides, during the solubilisation of calcium and magnesium appeared to decrease the extent of calcium solubilisation at pH 6.0 and 8.0. The results herein have implications for the choice of optimal pH conditions for the sustained release of calcium and magnesium from marine mineral sources.     

Isolation of antimicrobial agent from the marine algae Cystoseira hakodatensis

Cystoseira hakodatensis is an unutilised brown algae belonging to family Sargassaceae. A crude methanol extract from the algae showed inhibitory effects on the growths of Bacillus cereus and Bacillus licheniformis. To isolate the major antimicrobial agent, a sequential active‐guided isolation procedure was applied: liquid–liquid extraction, column chromatography and bio‐autography. A marked antimicrobial agent (active α) was isolated in hydrophobic fraction and was determined to phenolics without carbohydrates and proteins by phytochemical test. Regarding the antimicrobial potential, the isolated active α showed better inhibitory effects against B. cereus and B. licheniformis at 2 and 4 times of lower concentrations (62.5 and 31.3 μg mL^?1) in comparison with epigallocatechin gallate. These results showed that C. hakodatensis is a potential source of antimicrobial agent capable of preventing the growth of the two bacteria.     

Identification of long-chain perfluorinated acids in biota from the Canadian Arctic

Recently it was discovered that humans and animals from various urban and remote global locations contained a novel class of persistent fluorinated contaminants, the most pervasive of which was perfluorooctane sulfonate (PFOS). Lower concentrations of perfluorooctanoate, perfluorohexane sulfonate, and heptadecafluorooctane sulfonamide have also been detected in various samples. Although longer perfluoroalkyl carboxylates (PFCAs) are used in industry and have been detected in fish following a spill of aqueous film forming foam, no studies have been conducted to examine the widespread occurrence of long-chain PFCAs (e.g., CF3(CF2)xCOO-, where x > 6). To provide a preliminary assessment of fluorinated contaminants, including PFCAs, in the Canadian Arctic, polar bears, ringed seals, arctic fox, mink, common loons, northern fulmars, black guillemots, and fish were collected at various locations in the circumpolar region. PFOS was the major contaminant detected in most samples and in polar bear liver was the most prominent organohalogen (mean PFOS = 3.1 microg/g wet weight) compared to individual polychlorinated biphenyl congeners, chlordane, or hexachlorocyclohexane-related chemicals in fat. Using two independent mass spectral techniques, it was confirmed that all samples also contained ng/g concentrations of a homologous series of PFCAs, ranging in length from 9 to 15 carbons. Sum concentrations of PFCAs (sum(PFCAs)) were lower than total PFOS equivalents (sum(PFOS)) in all samples except for mink. In mink, perfluorononanoate (PFNA) concentrations exceeded PFOS concentrations, indicating that PFNA and other PFCAs should be considered in future risk assessments. Mammals feeding at higher trophic levels had greater concentrations of PFOS and PFCAs than mammals feeding at lower trophic positions. In general, odd-length PFCAs exceeded the concentration of even-length PFCAs, and concentrations decreased with increasing chain length in mammals. PFOS and PFCA concentrations were much lower for animals living in the Canadian Arctic than for the same species living in mid-latitude regions of the United States. Future studies should continue to monitor all fluorinated contaminants and examine the absolute and relative toxicities for this novel suite of PFCAs.     

Supercritical fluid extraction and characterization of lipids from algae scenedesmus obliquus

Supercritical carbon dioxide (SC‐CO₂) extractions (with and without ethanol as an entrainer) were carried out to remove lipids and pigments from protein concentrate of green algae (Scenedesmus obliquus) cultivated under controlled conditions. The content and fatty acid composition of algal lipids using column, thin‐layer (TLC) and gas‐liquid chromatography (GLC) were determined. Absorption spectra of extracted fractions showed the predominance of chlorophyll A (λ_max at 410nm). Single step supercritical carbon dioxide (SC‐CO₂) extraction resulted mostly in removal of neutral lipids and a part of glycolipids, but phospholipids were not extracted. Addition of ethanol to SC‐CO₂ increased the amount of glycolipids and phospholipids in the extract. TLC pattern of algal lipids showed that the main part of neutral lipids consisted of diglycerides, triglycerides, hydrocarbons, free sterols, and sterol esters. The glycolipids were mostly monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. In phospholipids, phosphatidyl choline, phosphatidyl glycerol, and phosphatidyl ethanolamine were the main compounds. Fatty acid composition patterns indicated the main fatty acids to be 16:0, 16:1, 16:2, 16:3, 16:4, 18:1, 18:2 and 18:3(a). Relatively high recovery of polyunsaturated fatty acids and essential fatty acids in supercritical fluid extracted algal lipids and protein isolates were observed.     

Extraction,structure and biofunctional activities of laminarin from brown algae

Brown algae are rich sources of bioactive compounds such as polysaccharides, peptides, omega‐3 fatty acids, carotenoids, phenolics, vitamins and minerals. Laminarin is low‐molecular‐weight polysaccharide and bioactive compound present in brown algae. Laminarin is found in the fronds of Laminaria and Saccharina species. Laminarin, a storage β‐glucan, is composed of (1,3)‐β‐d ‐glucan and some β‐(1,6)‐intrachain links. The reported content of laminarin from brown algae is up to levels of 35% on dry basis, which varies depending on species, harvesting season, habitat and method of extraction. Laminarin has many reported biofunctional activities including antitumour, anti‐apoptotic, anti‐inflammatory, anticoagulant and antioxidant activity. Biofunctional activities of laminarin can be enhanced after suitable chemical modifications, sulphation and novel processing techniques. Studies on feeding of laminarin‐rich extracts to animals indicate it's suitability as functional ingredient for food applications. This paper reviews the main sources, structure and extraction of laminarin with its biofunctional activities.     

Supercritical fluid extraction and characterization of lipids from algae Scenedesmus obliquus

Supercritical carbon dioxide (SC-CO2) extractions (with and without ethanol as an entrainer) were carried out to remove lipids and pigments from protein concentrate of green algae (Scenedesmus obliquus) cultivated under controlled conditions. The content and fatty acid composition of algal lipids using column, thin-layer (TLC) and gas-liquid chromatography (GLC) were determined. Absorption spectra of extracted fractions showed the predominance of chlorophyll A (lambda max at 410 nm). Single step supercritical carbon dioxide (SC-CO2) extraction resulted mostly in removal of neutral lipids and a part of glycolipids, but phospholipids were not extracted. Addition of ethanol to SC-CO2 increased the amount of glycolipids and phospholipids in the extract. TLC pattern of algal lipids showed that the main part of neutral lipids consisted of diglycerides, triglycerides, hydrocarbons, free sterols, and sterol esters. The glycolipids were mostly monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. In phospholipids, phosphatidyl choline, phosphatidyl glycerol, and phosphatidyl ethanolamine were the main compounds. Fatty acid composition patterns indicated the main fatty acids to be 16:0, 16:1, 16:2, 16:3, 16:4, 18:1, 18:2, and 18:3(a). Relatively high recovery of polyunsaturated fatty acids and essential fatty acids in supercritical fluid extracted algal lipids and proteins isolates were observed.     

Plasma-associated halogenated phenolic contaminants in benthic and pelagic fish species from the Detroit River

Halogenated phenolic contaminants (HPCs), polychlorinated biphenyls (PCBs), and other organochlorine (OC) contaminants (DDTs, chlordanes, HCH, and octachlorostyrene (OCS)) were determined (ng/g, wet wt basis) in the blood plasma of 6 piscivorous/pelagic- and 7 benthic-feeding fish species from the Detroit River. Seven to twelve hydroxylated (OH) PCB congeners with pentachloro- to nonachloro-substitution, pentachlorophenol (PCP) and 4-OH-heptachlorostyrene (4-OH-HpCS), as well as a number of other unidentified HPCs, were detected in all the fish species studied. The concentrations of sigma-OH-PCB (0.57-129.5 ng/ g), 4-OH-HpCS (0.02-0.31 ng/g), and PCP (0.05-3.42 ng/ g) in comparison to other major polychlorinated contaminants (sigma-PCB (10.4-909.0 ng/g), sigma-chlordane (0.72-8.68 ng/g), sigma-DDT (2.10-66.57 ng/g), and sigma-HCH (0.04-0.84 ng/g)) demonstrate the importance of HPCs, especially OH-PCBs, as plasma-associated contaminants. OH-PCBs are most likely metabolites of PCBs, and 4-OH-HpCS is a likely metabolite of OCS. Our findings indicate that metabolic biotransformation is a factor in the bioaccumulation, pharmacokinetics, and fate of OCS and highly chlorinated PCB congeners that are generally more recalcitrant in fish. Target tissue exposure to circulating OH-PCBs was variable, and thus potential OH-PCB-mediated toxicological activity and effects (e.g., endocrine-related) and health risks are different among the fish species.