Enhanced Exoglucanase Production by Brown Rot Fungus Fomitopsis sp. RCK2010 and its Application for Cellulose Saccharification

Exoglucanase production by brown rot fungus Fomitopsis sp. RCK2010 was optimized under solid-state fermentation using Plackett–Burman design (PBD) and response surface methodology (RSM). Four fermentation variables (moisture, inoculum level, casein, and Triton X-100) were identified to effect cellulase production significantly by PBD, which were further optimized using RSM of central composite design. An overall 130 % increase in enzyme production was achieved by the optimization of variables using statistical approaches. Moreover, crude cellulase from Fomitopsis sp. RCK2010 was applied to saccharify pretreated Prosopis juliflora (cellulosic fraction), which resulted in the release of 327.35 mg/g of reducing sugars that could further be utilized for bioethanol production.     

一株红球菌脱硫菌株脱硫特性的研究

从炼油厂污水排放口取得的土样中筛选到一株能降解二苯并噻吩 (DBT)的菌株 ,用GC/MS方法 ,证明其降解DBT走硫专一脱除途径 ,即“4S途径” .该菌株被命名为SDUZAWQ ,用微生物生理生化实验及 16SrDNA序列分析初步鉴定为红球菌属 (Rhodococcussp .) .实验结果表明 ,红球菌SDUZAWQ可有效降解苯并噻吩 (BT)和DBT及其甲基衍生物 .在 2d内 ,BT与DBT可同时完全降解 ,0 .5mmol·L-1的BT在 1d内可降解掉 86% ,降解速度高于DBT的降解 .5 MBT的降解率也高于 4,6 DMDBT和 4 MDBT .4 MDBT较 4,6 DMDBT更难降解 ,在 2d内 ,红球菌SDUZAWQ可降解 62 %的 4,6 DMDBT ,而相同条件下 ,4 MDBT仅能被降解 3 6% .     

Biodegradation of Crude Oil by a Newly Isolated Strain Rhodococcus sp. JZX-01

A highly efficient oil-degrading bacteria JZX-01 was isolated from the oil-contaminated soil of the seacoast near the Boxi Offshore Oil Field of China. Morphological, physiological, and 16S rDNA gene sequence analyses indicated that JZX-01 was assigned to the genus Rhodococcus sp. This strain decomposed 65.27?±?5.63 % of the crude oil in 9 days. Gas chromatography–mass spectrometry analysis showed that even the long-chain hydrocarbons (C31–C38) and branched alkanes (pristine and phytane), which were regarded as the stubborn ones, could be degraded. Further study showed that the bacteria still has good oil degradation ability at low temperatures as well as under high salt conditions. Moreover, JZX-01 was found to have a biosurfactant-producing capacity, which significantly favors the surface tension reduction and crude oil degradation. The promising isolated strain Rhodococcus sp. JZX-01 could be further used for the bioremediation of oil-polluted soil or seawater in a wide range of temperatures and high salt conditions.     

A Novel Alkaliphilic Xylanase from the Newly Isolated Mesophilic Bacillus sp. MX47: Production, Purification, and Characterization

A newly isolated bacterial strain, Bacillus sp. MX47, was actively producing extracellular xylanase only in xylan-containing medium. The xylanase was purified from the culture broth by two chromatographic steps. The xylanase had an apparent molecular weight of 26.4?kDa with an NH₂-terminal sequence (Gln-Gly-Gly-Asn-Phe) distinct from that of reported proteins, implying it is a novel enzyme. The optimum pH and temperature for xylanase activity were 8.0 and 40?°C, respectively. The enzyme activity was severely inhibited by many divalent metal ions and EDTA at 5?mM. The xylanase was highly specific to beechwood and oat spelt xylan, however, not active on carboxymethyl cellulose (CMC), avicel, pectin, and starch. Analysis of the xylan hydrolysis products by Bacillus sp. MX47 xylanase indicated that it is an endo-??-1,4-xylanase. It hydrolyzed xylan to xylobiose as the end product. The K _m and V _max values toward beechwood xylan were 3.24?mg?ml^?1 and 58.21???mol?min^?1?mg^?1 protein, respectively.     

Phytotoxic Metabolites Isolated from Aspergillus sp., an Endophytic Fungus of Crassula arborescens

Aspergillus sp., an endophytic fungus isolated from Crassula arborescens, displayed potent inhibitory activity against the seed germination of Arabidopsis thaliana. The bioactivity-guided fractionation of the culture extract of Aspergillus sp. MJ01 led to the isolation of nine compounds, including one previously undescribed furanone, namely aspertamarinoic acid (1), and eight known compounds, (−)-dihydrocanadensolide (2), kojic acid (3), citreoisocoumarin (4), astellolide A (5), astellolide B (6), astellolide G (7), cyclo-N-methylphenylalanyltryptophenyl (8) and (−)-ditryptophenaline (9). In the evaluation of the phytotoxic activities of compounds 1–9, the results suggested that 1 and 5 showed significant inhibitory activity on the seed germination of A. thaliana. This is the first report to disclose the phytotoxic activity of these compounds.     

Chemical Constituents of the Endophytic Fungus Phomopsis sp. A240 Isolated from Taxus chinensis var. mairei

A new sesquiterpene, eremophil‐9‐ene‐11,12,13‐triol ( 1 ), a new oxazole, 4‐(2‐hydroxyethyl)‐5‐methyloxazole ( 2 ), and the two known lactones, 5′‐hydroxyalternariol ( 3 ) and alternariol ( 4 ), were isolated from the extract of Phomopsis sp. A240, an endophytic fungus isolated from the bark of Taxus chinensis var. mairei. The structures of the isolated compounds were determined by analyses of their spectroscopic data, as well as by comparison with literature reports. The isolated compounds were evaluated for their cytotoxic and antioxidant activities.     

Degradation of Alkylphenols by White Rot Fungus Irpex lacteus and Its Manganese Peroxidase

Alkylphenols are common endocrine disrupters that are produced from the degradation of widely used surfactants. Since they cause various harmful effects on aquatic life and in humans, they should be removed from the environments being contaminated. White rot fungus Irpex lacteus can completely degrade 100?mg/L of octylphenol, nonylphenol, and phenylphenol during 1?day of incubation in the complex YMG medium, which was the highest degrading capability among nine strains of white rot fungi tested. In the N-limited Kirk??s basal salts medium, I. lacteus could degrade almost 100?% of 100?mg/L octylphenol and nonylphenol in 1?h, and exhibited a high activity of manganese peroxidase (MnP; 1,790?U/L). MnP of I. lacteus was purified by ion exchange chromatography, and this degraded 99?% of 50?mg/L octylphenol and removed 80?% of estrogenic activity in 2?hours. In addition, the purified MnP (10?U/mL) degraded over 90?% of 50?mg/L nonylphenol in 1?h.     

从红树林内源真菌2526#分离到Sterigmatocystin

从海洋资源中寻找药物已越来越受到重视 ,已有的研究表明海洋资源有可能成为治疗人类疑难病症和延年益寿药物的丰富源泉[1] 。本研究组在从海洋微生物筛选新药的过程中 ,已发现多种结构奇特而具有强生理活性的化合物[2～ 4 ] 。Ｓｔｅｒｉｇｍａｔｏｃｙｓｔｉｎ最早分离自陆生真菌Ａｓｐｅｒｇｉｌｌｕｓｖｅｒｓｉｃｏｌｏｒ的代谢产物[5] ,随后人们对其结构、生源合成及药理活性进行了广泛的研究。结果表明 ,ｓｔｅｒｉｇｍａｔｏｃｙｓｔｉｎ是细胞毒性更强的化合物ＡｆｌａｔｏｘｉｎＢ1的生源合成前体。本文报道从采自香港红树Ａｖｉ…     

A New Cyclic Peptide and a New Steroid from the Fungus Penicillium sp. GD6 Isolated from the Mangrove Bruguiera gymnorrhiza

A rare new cyclic tetrapeptide, 5,5′‐epoxy‐MKN‐349A ( 1 ), featured by a MKN‐349A ( 5 ) skeleton and containing an uncommon ether bridge between C(5) and C(5′), and a new steroid, named 11‐O‐acetyl‐NGA0187 ( 2 ), together with two known steroids, 3 and 4 , were isolated from an endophytic fungus Penicillium sp. GD6 associated with the Chinese mangrove Bruguiera gymnorrhiza. The structures of the new compounds were elucidated on the basis of extensive spectroscopic analyses and by comparison with the data of related compounds reported in literature. Neither of the compounds 3 and 4 , isolated in this study, showed obvious bioactivities in the antibacterial bioassay experiments.     

Two-Staged Temperature and Agitation Strategy for the Production of Transglutaminase from a Streptomyces sp. Isolated from Brazilian Soils

Transglutaminase catalyzes the cross-linking reaction between a glutamine residue and a free amine residue of proteins leading to the formation of protein aggregates. In this research, the effects of temperature, agitation, and aeration on the production of transglutaminase in a bench reactor by a newly isolated Streptomyces sp. from Brazilian soils were investigated using a factorial experimental design. The parameters evaluated influenced the enzyme production, and the data showed that the best conditions to enhance cell growth were different from those leading to enhanced transglutaminase production. Thus, a temperature and agitation shift strategy was adopted to increase transglutaminase productivity. The temperature and agitation were first set at 34 °C and 350 rpm, respectively, and after 24 h decreasing to 26 °C and 150 rpm until the end of fermentation. The transglutaminase activity obtained was 2.18 U/mL after 42 h of fermentation, which was twice than that obtained using a constant temperature and agitation fermentation strategy.     

Xylanase Isozymes from the Newly Isolated Bacillus sp. CKBx1D and Optimization of Its Deinking Potentiality

Recycling of civic paper waste by enzyme-based technology is nowadays a point of much concern for pollution-less green environment. In this study, the deinking effectiveness of purified xylanase from a newly isolated bacterium was evaluated for recycling of laser jet paper waste. A potent xylanases-producing bacterium from the microbial consortia of termite gut was isolated, which was further identified on the basis of 16S rRNA sequence as Bacillus sp. CKBx1D. In submerged fermentation condition, the isolate produced the highest level of xylanase (480?U/ml) at 36?h of growth. The extracellular xylanase system comprises of three distinct isozymes (est. Mw 35.28, 28.63, 18.94?kDa). The deinking of laser printed paper waste was performed using the purified enzyme mixture. Whole operational parameters were optimized using the Response Surface Methodology; it was found that at pH 6.8 with 47.2?h of continuous shaking at constant temperature of 35?°C, enzymes showed best deinking activity. After enzyme treatment, the physical properties of the pulp like brightness and ERIC (effective residual ink content) values were enhanced, whereas the pulp opacity was more reduced than the control treatment. Hence, the bacterial isolate and its xylanolytic enzyme system could efficiently be used in recycling paper waste as deinking agent.     

Novel Polyketides Isolated from Streptomyces sp.

From the endophytic strain Streptomyces sp. CS of Maytenus hookeri, five novel type III polyketides, compounds 1 – 5 , were isolated. Their structures were elucidated by spectroscopic analyses including 1D‐ and 2D‐NMR experiments, and by HR‐ESI‐MS.     

Two New Sesquiterpenes from the Fungus Stereum sp.

Two new sesquiterpenes, stereumin F ( 1 ) and stereumin G ( 2 ), together with two known compounds (3β,5α,22E,24R)‐5,8‐epidioxyergosta‐6,22‐dien‐3‐ol ( 3 ) and 4‐(2‐hydroxyethyl)phenol ( 4 ), were isolated from the AcOEt extract of the culture broth and the MeOH extract of the mycelium of the fungal strain Stereum sp. CCTCC AF 207024. Their structures were established on the basis of spectral analyses.     

Cylindromicin from Arctic-Derived Fungus Tolypocladium sp. SCSIO 40433

The fungus strain SCSIO 40433 was isolated from an Arctic-derived glacier sediment sample and characterized as Tolypocladium cylindrosporum. A new compound, cylindromicin (1), and seven known secondary metabolites (2–8) were isolated from this strain. The chemical structures of these compounds were elucidated by comprehensive spectroscopic analyses. Cylindromicin (1) featured a 3,4-dihydro-2H-pyran skeleton. The absolute configuration of compound 1 was assigned via interpretation of key Nuclear Overhauser Effect Spectroscopy (NOESY) correlations and Electronic Circular Dichroism (ECD) calculation. Cylindromicin (1) exhibited significant tyrosinase inhibition activity. This study highlights Polar fungi as a potential resource for new bioactive natural products.     

A new polyoxygenated farnesylcyclohexenone from Fungus Penicillium sp.

A new polyoxygenated farnesylcyclohexenone, peniginsengin A (1), was isolated from the fermentation of Penicillium sp. YIM PH30003, an endophytic fungus associated with Panax notoginseng (Burk.) F. H. Chen. The structure was assigned based on a combination of 1 D and 2 D NMR and mass spectral data. The cytotoxicity and antimicrobial activities of compound 1 were investigated.     

Efficient Enantioselective Biocatalytic Production of a Chiral Intermediate of Sitagliptin by a Newly Filamentous Fungus Isolate

(S)-3-Hydroxy-1-(3-(trifluoromethyl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)-4-(2,4,5-trifluorophenyl)butan-1-one ((S)-HTPP) is a crucial intermediate for the synthesis of Sitagliptin. A fungal strain ZJPH1308, capable of the biocatalysis of ketoamide 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-one (OTPP) to (S)-HTPP with excellent enantioselectivity, was isolated from a soil sample and identified as Rhizopus microsporus var. rhizopodiformis ZJPH1308 based on its morphological characteristics and internal transcribed spacer (ITS) sequence. Some key reaction parameters involved in the bioreduction catalyzed by isolate ZJPH1308 were then optimized. It demonstrated that the bioreduction of OTPP was effective conducted at relative high temperature (45 °C), along with distilled water as reaction medium and glycerol-coupling approach for cofactor regeneration. Under the optimal conditions, the preparative-scale bioreduction gave a 93.2 % yield (with >99.9 % of enantiomeric excess (ee)) at 15 mM of OTPP and 45 °C, reaction for 24 h. The results indicated that fungal isolate ZJPH1308 can afford a thermostable carbonyl reductase and is a promising biocatalyst for clean and efficient production of valuable chiral intermediate.