Modulation of polyunsaturated fatty acids in mixotrophic Karlodinium veneficum (Dinophyceae) and its prey,Storeatula major (Cryptophyceae)1

We examined whether fatty acid (FA) composition changed when Karlodinium veneficum (D. Ballantine) J. Larsen (Dinophyceae) was grown phototrophically or mixotrophically on Storeatula major Butcher ex D. R. A. Hill (Cryptophyceae). We hypothesized that the FA composition of mixotrophic K. veneficum would not change relative to the FA composition of phototrophic K. veneficum. As in other phototrophic dinoflagellates, octadecapentaenoic acid (18:5n3) represented 9% to 20% of total FA in K. veneficum and was enriched within chloroplast‐associated galactolipid classes. The 18:5n3 content showed a highly significant positive correlation (r² = 0.95) with chl a content and a highly significant negative correlation with growth rate (r² = 0.88). A previously undescribed chloroplast galactolipid molecular species, digalactosyldiacylglycerol (DGDG; 18:5n3/18:5n3), was a dominant structural lipid in K. veneficum. Docosahexaenoic acid (22:6n3) represented 14% to 19% of total K. veneficum FA and was enriched within phospholipids. In the prey S. major, 18:5n3 was not present, but octadecatetraenoic acid (18:4n3) and α‐linolenic acid (18:3n3) represented approximately 50% of total FA and were enriched within chloroplast‐associated galactolipid classes. Eicosapentaenoic acid (20:5n3) and 22:6n3 represented approximately 18% of total FA in S. major and were enriched within phospholipids. The FA profile of mixotrophic K. veneficum, compared to phototrophic K. veneficum, showed elevated levels of 18:3n3, 18:4n3, and 20:5n3, and lower but persistent levels of 18:5n3. Production to ingestion (P:I) ratios >1 for major polyunsaturated fatty acids (PUFAs) indicated that direct assimilation from prey under balanced growth could not support rates of PUFA production in mixotrophic K. veneficum. These data suggest that the plastid plays a continuing and essential role in lipid metabolism during mixotrophic growth.     

Production and potential biotechnological applications of microbial surfactants: An overview

Microbial surfactants are amphipathic molecules that consist of hydrophilic and hydrophobic domains, which allow partition of two fluid phases of varying degree of polarity. They are classified into two main groups: bioemulsifier and biosurfactant, depending on their molecular weight. Microbial surfactants occur in various categories according to their chemical nature and producing organisms. These biomolecules are produced by diverse groups of microorganisms including fungi, bacteria, and yeasts. Their production is significantly influenced by substrate type, fermentation technology and microbial strains. Owing to inherent multifunctional properties and assorted synthetic aptitude of the microbes, microbial surfactants are mostly preferred than their chemical counterparts for various industrial and biomedical applications including bioremediation, oil recovery; as supplements in laundry formulations and as emulsion-stabilizers in food and cosmetic industries as well as therapeutic agents in medicine. The present review discusses on production of microbial surfactants as promising and alternative broad-functional biomolecules for various biotechnological applications.     

Antioxidant,Anti‐inflammatory and Cytotoxic Activities of Polyphenols Extracted from Chroogomphus rutilus

Chroogomphus rutilus is a rare fungal species that grows under pine trees and is now widely used as a functional food and pharmaceutical product. However, the chemical constituents and biological activities of Chroogomphus rutilus have been relatively limited. The present study aimed at determining the total polyphenols and flavonoids contents, biological activities and main phenolic compounds of Chroogomphus rutilus from different geographical origins at the stipe and pileus. The results suggested that Chroogomphus rutilus polyphenol extracts revealed a higher antioxidant, anti‐inflammatory, and cytotoxic activities, and there were significant differences between samples from different locations and regions. Correlation analysis showed that the contents of total polyphenols and flavonoids were significantly correlated with antioxidant and anti‐inflammatory activities. However, only the content of total flavonoids was significantly correlated with cytotoxicity, which means that the cytotoxicity of Chroogomphus rutilus polyphenol extracts may be regulated by flavonoids or other compounds. HPLC‐DAD analysis revealed that the main phenolic compound was protocatechuic acid, followed by baicalin, p‐hydroxyphenylacetic acid and p‐hydroxybenzoic acid, but comparing with the pileus extracts, the stipe extracts can be considered as a higher concentration of phenolic compounds. Therefore, antioxidant, anti‐inflammatory and cytotoxic activities of Chroogomphus rutilus polyphenol extracts could be due to the identified compounds. This study investigated a deep knowledge about the constituents and activities of Chroogomphus rutilus and provided the reference for its application in food and pharmaceutical.     

珍稀名贵食药用真菌块菌属的化学成分及药理活性研究进展

块菌属Tuber是一类珍贵的地下生外生菌根食药用真菌,能与多种高等树木的根系形成互利共生关系,具有重要的经济和生态价值.一些种类因其地下生的子囊果具有独特的香味被认为是美食界的奢侈品而享誉全球.作为国际著名贸易真菌种类,块菌的研究在最近的二三十年里受到国内外的广泛关注.本文重点从块菌的化学成分及药理活性2个方面对近10...     

产铁载体菌株的分离、培养条件优化及初步应用

[背景]微生物菌肥是推动绿色农业发展的关键.铁载体是由植物根际微生物产生的一类低分子量金属离子螯合物,可通过螯合Fe3+促进植物生长,因此,筛选具有高产铁载体功能的菌种意义重大.[目的]从植株根际土壤中分离高产铁载体微生物,为开发植物根际促生菌提供种质资源.[方法]采用chrome azurol sulfonate(C...     

A novel tool for medium optimization and characterization in the early stages of a metabolite production process

A new parameter could be introduced to facilitate the optimization of media used for cultivation of stock cultures on agar slants. This parameter reduces the amount of data generated in optimization experiments to one single value (hs-value) for each medium composition. The hs-value (high and stable product formation) allows an assessment of any medium formulation with regard to reproducibility and product formation, demonstrated for the production process of the antibiotic gallidermin by Staphylococcus gallinarum TÜ 3928. © Rapid Science Ltd. 1998     

Phytases: crystal structures, protein engineering and potential biotechnological applications

Phytases are a group of enzymes capable of releasing phosphates from phytates, one of the major forms of phosphorus (P) in animal feeds of plant origin. These enzymes have been widely used in animal feed to improve phosphorus nutrition and to reduce phosphorus pollution in animal waste. This review covers the basic nomenclature and crystal structures of phytases and emphasizes both the protein engineering strategies used for the development of new, effective phytases with improved properties and the potential biotechnological applications of phytases.     

Two new phospholipase D isoforms of Loxosceles laeta: cloning, heterologous expression, functional characterization, and potential biotechnological application

Toxin phospholipases-D present in the venom of Loxosceles spiders is the principal responsible for local and systemic effects observed in the loxoscelism. In this study, we describe the cloning, expression, functional evaluation, and potential biotechnological application of cDNAs, which code for two new phospholipase D isoforms, LIPLD1 and LIPLD2, of the spider Loxosceles laeta. The recombinant protein rLIPLD1 had hydrolytic activity on sphingomyelin and in vitro hemolytic activity on human red blood cells, whereas rLIPLD2 was inactive. The purified recombinant proteins and the venom are recognized by polyclonal anti-rLIPLD1 and rLIPLD2 sera produced in animals and conferred immunoprotection against the venom. These new isoforms reinforce the importance of the multigene family of phospholipases-D present in Loxosceles spiders. A highly immunogenic inactive isoform such as rLIPLD2 raises important expectation for its use as a potential immunogenic inducer of the immunoprotective response to the toxic action of the venom of Loxosceles laeta.     

Therapeutic potential of culinary-medicinal mushrooms for the management of neurodegenerative diseases: diversity,metabolite, and mechanism

Mushrooms have long been used not only as food but also for the treatment of various ailments. Although at its infancy, accumulated evidence suggested that culinary-medicinal mushrooms may play an important role in the prevention of many age-associated neurological dysfunctions, including Alzheimer’s and Parkinson’s diseases. Therefore, efforts have been devoted to a search for more mushroom species that may improve memory and cognition functions. Such mushrooms include Hericium erinaceus, Ganoderma lucidum, Sarcodon spp., Antrodia camphorata, Pleurotus giganteus, Lignosus rhinocerotis, Grifola frondosa, and many more. Here, we review over 20 different brain-improving culinary-medicinal mushrooms and at least 80 different bioactive secondary metabolites isolated from them. The mushrooms (either extracts from basidiocarps/mycelia or isolated compounds) reduced beta amyloid-induced neurotoxicity and had anti-acetylcholinesterase, neurite outgrowth stimulation, nerve growth factor (NGF) synthesis, neuroprotective, antioxidant, and anti-(neuro)inflammatory effects. The in vitro and in vivo studies on the molecular mechanisms responsible for the bioactive effects of mushrooms are also discussed. Mushrooms can be considered as useful therapeutic agents in the management and/or treatment of neurodegeneration diseases. However, this review focuses on in vitro evidence and clinical trials with humans are needed.     

Purification,structural characterization and biotechnological potential of tannase enzyme produced by Enterobacter cloacae strain 41

Tannase production by Enterobacter cloacae strain 41 was investigated under submerged fermentation which was optimized at various circumstances such as pH, temperature, substrate, and agitation, carbon, and nitrogen sources. Tannase was purified by a two-step approach comprising of ion exchange and size exclusion chromatography, respectively. The maximum tannase production was achieved at 1.0% tannic acid concentration, incubation temperature of 50 °C, and initial pH 6.0. The molecular weight of purified tannase was 45 kDa on 10% SDS-PAGE, and it was confirmed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS). The enzymatic products of purified tannase were characterized by HPLC, TLC and FT-IR spectroscopy which showed the functional groups such as OH, CO, and CC. The purified tannase retained the activity up to 90% under the condition at 50 °C and pH 6.0 after 1 h incubation. Enzyme kinetics and inhibition studies were also investigated. Cytotoxicity studies showed that the tannase has no cytotoxic effects on Vero cell line. The results indicated the E. cloacae strain 41 would give a potential source for the efficient production of tannase and can be used in tannery effluent degradation, food, and pharmaceutical industrial applications.     

Glucuronoyl esterases: diversity,properties and biotechnological potential. A review

Glucuronoyl esterases (GEs) belonging to the carbohydrate esterase family 15 (CE15) are involved in microbial degradation of lignocellulosic plant materials. GEs are capable of degrading complex polymers of lignin and hemicellulose cleaving ester bonds between glucuronic acid residues in xylan and lignin alcohols. GEs promote separation of lignin, hemicellulose and cellulose which is crucial for efficient utilization of biomass as an energy source and feedstock for further processing into products or chemicals. Genes encoding GEs are found in both fungi and bacteria, but, so far, bacterial GEs are essentially unexplored, and despite being discovered >10?years ago, only a limited number of GEs have been characterized. The first laboratory scale example of improved xylose and glucuronic acid release by the synergistic action of GE with cellulolytic enzymes was only reported recently (improved C5 sugar and glucuronic acid yields) and, until now, not much is known about their biotechnology potential. In this review, we discuss the diversity, structure and properties of microbial GEs and consider the status of their action on natural substrates and in biological systems in relation to their future industrial use.     

Sorghum: Nutritional Factors,Bioactive Compounds,Pharmaceutical and Application in Food Systems: A Review

After wheat, rice, maize, and barley, sorghum is the fifth most widely grown cereal on the planet. Due to its highproduction, drought resistance, and heat tolerance, this crop is replacing maize in some areas. Sorghum is available in a variety of colors, including cream, lemon-yellow, red, and even black. The principal grain anatomicalcomponents are pericarp, germ or embryo and endosperm. This review provides an overview of key sorghumgrain components, including starches, fiber, proteins, lipids, and vitamins. Also, we summarized phenolic compounds, flavonoids, tannins, carotenoids, vitamin E, amines, Policosanols and Phytosterols in sorghum grains.Sorghum is used to manufacture bread and porridge, and it provides a significant source of energy and nutritionfor humans; sorghum is extensively farmed for animal feed. However, because the natural components in sorghum are useful in the development of healthy and functional foods, sorghum farming for both biofuel production and human consumption is gaining popularity. Pigmented sorghum grain is high in antioxidants such aspolyphenols, primarily tannins, which have a variety of health benefits, including antiproliferative propertieslinked to the prevention of certain cancers, antioxidant activities linked to the prevention of diseases linked tooxidative stress, and anti-inflammatory effects, as well as improving glucose metabolism. Because these chemicalscannot be assimilated, their application in the food business has been limited, as sorghum is regarded as a lownutritional grain due to the presence of anti-nutritional components such as strong tannins, which form complexes with proteins and iron, limiting their digestibility. This review aims to show the utilization of sorghumas a source of bioactive chemicals and the value they bestow on human health due to the general biological potential it possesses.     

Lipase of Pseudomonas cepacia for biotechnological purposes: purification,crystallization and characterization

Commercial lipase (triacylglycerol lipase, EC 3.1.1.3) of Pseudomonas cepacia (Amano) has been purified to homogeneity by a single chromatography on phenyl Sepharose. The eluted lipase crystallized spontaneously at 4°C in the eluent, containing 58–69% 2-propanol. The yield of the lipase was 87–100% and the specific activity during the hydrolysis of triolein 5800 U/mg protein. This protein has a molecular weight of 34.1 kDa as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Its purity was determined by SDS-Page and capillary zone electrophoresis to be ≥ 99%. Immobilization on Sepharose increased its stability in organic solvents. This lipase of P. cepacia differs from that of other Pseudomonas strains in respect of substrate specificity and during crystallization. It exhibits a high stability in organic solvents and supercritical carbon dioxide.     

Agrobacterium-mediated horizontal gene transfer: Mechanism,biotechnological application,potential risk and forestalling strategy

The extraordinary capacity of Agrobacterium to transfer its genetic material to host cell makes it evolve from phytopathogen to a powerful transgenic vector. Agrobacterium-mediated stable transformation is widely used as the preferred method to create transgenic plants for molecular plant biology research and crop breeding. Recent years, both mechanism and application of Agrobacterium-mediated horizontal gene transfer have made significant progresses, especially Agrobacterium-mediated transient transformation was developed for plant biotechnology industry to produce recombinant proteins. Agrobacterium strains are almost used and saved not only by each of microbiology and molecular plant labs, but also by many of plant biotechnology manufacturers. Agrobacterium is able to transfer its genetic material to a broad range of hosts, including plant and non-plant hosts. As a consequence, the concern of environmental risk associated with the accidental release of genetically modified Agrobacterium arises. In this article, we outline the recent progress in the molecular mechanism of Agrobacterium-meditated gene transfer, focus on the application of Agrobacterium-mediated horizontal gene transfer, and review the potential risk associated with Agrobacterium-meditated gene transfer. Based on the comparison between the infecting process of Agrobacterium as a pathogen and the transgenic process of Agrobacterium as a transgenic vector, we realize that chemotaxis is the distinct difference between these two biological processes and thus discuss the possible role of chemotaxis in forestalling the potential risk of Agrobacterium-meditated horizontal gene transfer to non-target plant species.     

Growth,biochemical and enzymatic responses of thermal cyanobacterium Gloeocapsa sp. (Cyanophyceae) to temperature and irradiance

The present study describes a strain of Gloeocapsa sp. designated as Gacheva 2007/R‐06/1, originally isolated from a geothermal flow located in Rupite, Bulgaria. To evaluate whether this cyanobacterium is locally adapted to hot environment or has the ability to tolerate lower temperatures, its growth, biochemical composition, enzyme isoforms and activity of the main antioxidant enzymes and proteases were characterized under various temperatures and two irradiance levels. The strain was able to grow over the whole temperature range (15–40°C) under two different photon fluence densities – 132 μmol photons m^?2 s^?1 (unilateral, low light, LL) and 2 × 132 μmol photons m^?2 s^?1 (bilateral, high light, HL). The best growth occurred at either 34°C and LL or at 36°C and HL, but significant growth inhibition was noted at 15°C and 40°C. Low temperature treatment (15°C) resulted in higher levels of total protein and an increased activity of manganese superoxide dismutase (MnSOD) and glutathione reductase, as compared to optimum growth temperatures. After simultaneous exposure to 15°C and HL, increases in lipid content and activity of iron superoxide dismutase and catalase (CAT) were also observed. Cultivation of cells at 40°C enhanced MnSOD, CAT and peroxidase activities, regardless of irradiance level. Increased total protein content and protease activity at 40°C was only associated with the HL treatment. Overall, these results indicate that Gloeocapsa sp. strain Gacheva 2007/R‐06/1 used different strategies to enable cells to efficiently acclimate and withstand adverse low or high temperatures. This strain obviously tolerates a wide range of temperatures below its natural habitat temperature, and does not seem to be locally adapted to its original thermal regime. It behaved as a thermotolerant rather than a thermophilic cyanobacterium, which suggests its wider distribution in nature.     

Evaluation of guanylhydrazone derivatives as inhibitors of Candida rugosa digestive lipase: Biological,biophysical, theoretical studies and biotechnological application

This work aimed to evaluate the inhibition of Candida rugosa lipase by five guanylhydrazone derivatives through biological, biophysical and theoretical studies simulating physiologic conditions. The compound LQM11 (IC₅₀ = 14.70 μM) presented the highest inhibition against the enzyme. Therefore, for a better understanding of the interaction process, spectroscopic and theoretical studies were performed. Fluorescence and UV–vis assays indicate a static quenching mechanism with non-fluorescent supramolecular complex formation and changing the native protein structure. The binding process was spontaneous (ΔG < 0) and electrostatic forces (ΔH < 0 and ΔS > 0) played a preferential role in stabilizing the complex ligand-lipase. The compounds were classified as non-competitive inhibitors using orlistat as a reference in competition studies. Based on the ¹H NMR assays it was possible to propose the sites of ligand (epitope) that bind preferentially to the enzyme and the theoretical studies were consistent with the experimental results. Finally, LQM11 was efficient as a lipase inhibitor of the crude intestinal extract of larvae of Rhynchophorus palmarum, an important agricultural plague, showing potential for control of this pest. Within this context, the real potential of this biotechnological application deserves further studies.     

The lipases from Yarrowia lipolytica: genetics, production, regulation, biochemical characterization and biotechnological applications

Lipases are serine hydrolases that catalyze in nature the hydrolysis of ester bonds of long chain triacylglycerol into fatty acid and glycerol. However, in favorable thermodynamic conditions, they are also able to catalyze reactions of synthesis such as esterification or amidation. The non-conventional yeast Yarrowia lipolytica possesses 16 paralogs of genes coding for lipase. However, little information on all those paralogs has been yet obtained and only three isoenzymes, namely Lip2p, Lip7p and Lip8p have been partly characterized so far. Microarray data suggest that only a few of them could be expressed and that lipase synthesis seems to be dependent on the fatty acid or oil used as carbon source confirming the high adaptation of Y. lipolytica to hydrophobic substrate utilization. This review focuses on the biochemical characterization of those enzymes with special emphasis on the Lip2p lipase which is the isoenzyme mainly synthesized by Y. lipolytica. Crystallographic data highlight that this latter is a lipase sensu stricto with a lid covering the active site of the enzyme in its closed conformation. Recent findings on enzyme conditioning in dehydrated or liquid formulation, in enzyme immobilization by entrapment in natural polymers from either organic or mineral origins are also discussed together with long-term storage strategies. The development of various biotechnological applications in different fields such as cheese ripening, waste treatment, drug synthesis or human therapeutics is also presented.