We investigated the effect of commercially available enzymes (α-amylase, α-galactosidase, papain, trypsin, and lipase) as well as proteases from deep-sea bacteria on the larval attachment of the ...bryozoan Bugula neritina L. The 50% effective concentrations (EC₅₀) of the commercial proteases were 10 times lower than those of other enzymes. Crude proteases from six deep-sea Pseudoalteromonas species significantly decreased larval attachment at concentrations of 0.03 to 1 mIU ml-¹. The EC₅₀ of the pure protease from the bacterium Pseudoalteromonas issachenkonii UST041101-043 was close to 1 ng ml-¹ (0.1 mIU ml-¹). The protease and trypsin individually incorporated in a water-soluble paint matrix inhibited biofouling in a field experiment. There are certain correlations between production of proteases by bacterial films and inhibition of larval attachment. None of the bacteria with biofilms that induced attachment of B. neritina produced proteolytic enzymes, whereas most of the bacteria that formed inhibitive biofilms produced proteases. Our investigation demonstrated the potential use of proteolytic enzymes for antifouling defense.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Microorganisms associated with invertebrate hosts have long been suggested to be a source for bioactive metabolites. In this study, we reported that a sponge-associated fungus, Letendraea ...helminthicola, produced two antifouling compounds: 3-methyl-N-(2-phenylethyl) butanamide and cyclo(D-Pro-D-Phe). To optimize the production of these antifouling compounds, we then examined the production of compounds under different culture conditions (temperature, salinity, pH, and carbon and nitrogen sources). This fungus grew well and produced more compounds at temperatures between 18 and 30°C; the fungus grew well at 75 parts per thousand (ppt) salinity but produced the highest amount of antifouling compounds at 30 and 45 ppt. The optimal initial pH value for mycelial growth was 5.5 to 6.5, whereas the production of the antifouling compounds was maximized at pH 3.5 and 4.5. Glucose and xylose (as carbon sources) increased the production of antifouling compounds. Yeast extract and peptone (as nitrogen sources) maximized the production of mycelial biomass and antifouling compounds. Our results indicate that culture conditions greatly affect the production of bioactive compounds from mycelial fungal cultures as exemplified by strain L. helminthicola and that the conditions favorable for fungal growth may not be the best conditions for bioactive compound production.
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CEKLJ, DOBA, EMUNI, FZAB, GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Trichoderma reesei Rut C-30 was cultivated in bioreactors at different pH on a medium with lactose as the main carbon source. Compared to an earlier study, in which
T.
reesei Rut C-30 was cultivated ...using polysaccharides (cellulose or xylan) as the main carbon sources, we now report a slightly lower pH value for maximal xylanase levels. The highest xylanase activity (IU/ml) on the lactose-based medium was observed at pH 6.0 compared to pH 7.0 on the polysaccharide-based media. When the pattern of different xylanases was analyzed by isoelectric focusing and activity zymogram, we observed that a low pH (4.0) favoured the production of xylanase I, whilst a high pH (6.0) favoured the production of xylanase III. Xylanase II was clearly produced at both pH values. The results at pH 4 and 6 correlate with the pH activity profiles of xylanase I, II and III. Hence, the different
T.
reesei xylanases were produced according to which enzyme is most active in that particular environment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The effects of culture conditions and chloramphenicol treatment on the induction of the marine bacterium Pseudoalteromonas spongiae to larval settlement of Hydroides elegans were investigated. The ...results showed that P. spongiae cells grown in the medium containing both yeast extract and peptone (YP-grown P. spongiae) was highly inductive to larval settlement, whereas P. spongiae cells grown in the medium containing only peptone (P-grown P. spongiae) or YP-grown P. spongiae cells treated with chloramphenicol at the onset of biofilm development (YPC-grown P. spongiae) did not induce larval settlement. Analysis of biofilm formation, biofilm structure, and the surface protein profile indicated that only the induction-capable YP-grown P. spongiae formed a well-developed biofilm, while the P-grown P. spongiae and the YPC-grown P. spongiae did not. We report here for the first time that bacterial biofilm formation was associated with its induction of larval settlement.
Disulphide bridges were introduced in different combinations into the N-terminal region and the single alpha-helix of mesophilic Trichoderma reesei xylanase II (TRX II). We used earlier ...disulphide-bridge data and designed new disulphide bridges for the combination mutants. The most stable mutant contained two disulphide bridges (between positions 2 and 28 and between positions 110 and 154, respectively) and the mutations N11D, N38E, and Q162H. With a half-life of approximately 56 h at 65 degrees C, the thermostability of this sevenfold mutant was approximately 5,000 times higher than that of TRX II, and the half-life was 25 min even at 75 degrees C. The thermostability of this mutant was approximately 30 times higher than that of the corresponding mutant missing the bridge between positions 2 and 28. The extensive stabilization at two protein regions did not alter the kinetic properties of the sevenfold mutant from that of the wild-type TRX II. The combination of disulphide bridges enhanced significantly the pH-dependent stability in a wide pH range.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The suitability of
L-arabinose-rich plant hydrolysates as carbon sources and inducers of xylanase production in
Trichoderma reesei Rut C-30 was tested. Significantly higher xylanase activities were ...obtained in cultures on oat husk and sugar beet pulp hydrolysates than on lactose. In batch culture with oat husk hydrolysate and lactose, the xylanase activity was about 9 times higher (∼510
IU/ml) than in lactose (∼60
IU/ml). Even higher xylanase activity (∼630
IU/ml) was obtained when the batch cultivations were done on sugar beet pulp hydrolysate and lactose. In a fed-batch culture using oat husk hydrolysate–lactose the xylanase activity was as high as 1350
IU/ml in 4 days. The cellulase production clearly decreased when
T.
reesei was cultured on both hydrolysates compared to the cultivation on lactose. Moreover, the relative amounts of the xylanases I–III were similar regardless the used carbon source.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Protein hydrolysates are easily digested and utilized by humans and animals, and are less likely to cause allergies. Protein hydrolysis caused by endopeptidases often leads to the exposure of ...hydrophobic amino acids at the ends of peptides, which consequently causes bitter taste. Microbial aminopeptidases remove the exposed hydrophobic amino acids at the ends of aminopeptides, which improves taste, allowing for easier production. This processe is attacking significant attention from industry and laboratories. Aminopeptidases selectively hydrolyze peptide bonds from the N-terminal of proteins or peptides to produce free amino acids. Aminopeptidases can be classified into leucine, lysine, methionine and proline aminopeptidases by hydrolyzed N-terminal residues; metallo-, serine- and cysteine- aminopeptidases by the reaction mechanisms; dipeptide and triphoptide enzymes by the released number of amino acid residues at the end of hydrolyzed peptides; or acidic, neutral and basic aminopeptidases by their optimal hydrolysis pH. Commercial aminopeptidases are generally produced by microbial fermentation, and are mainly applied in the debittering of protein hydrolysates, the deep hydrolysis of protein, and the production of condiments, cheese, and bioactive peptides, as well as for disease detection in the medical industry.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The fermentation of herbaceous peony black tea by enzyme is beneficial to improve the flavor quality. This work aimed to investigate the influence of withering and fermentation on the taste and aroma ...of herbaceous peony black tea by combining physical and chemical analysis, sensory evaluation, LC-QQQ and GC-QTOF. Physicochemical analysis and sensory evaluation determined that a withering degree of 30, fermentation time of 4 h and fermentation temperature of 28 °C improved the quality of herbaceous peony black tea. Moreover, LC-QQQ combined with sensory evaluation results showed that polyphenols (gallic acid and methyl gallate, catechin, (-)-epicatechin gallate, and naringenin) and monoterpenes (paeoniflorin and albiflorin) were significantly correlated with the astringency of herbaceous peony black tea (P < 0.05) and that fermentation could effectively reduce the astringency of herbaceous peony black tea. GC-QTOF combined with OPLS-DA (VIP > 1) identified 28 volatile components as key herbaceous peony black tea compounds. Compared with unfermented tea, the volatile components and contents were significantly increased by fermentation, and phenylethyl alcohol, 5-methylfurfural, cuminaldehyde, 1-(furan-2-yl) ethanone and o-cymene were formed. This study provides a theoretical basis and technical guidance for the comprehensive utilization and green development of herbaceous peony petal tea.
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•Withering and fermentation can improve the quality of herbaceous peony black tea.•Polyphenols and monoterpenes are the main astringent components.•28 volatile components are the key compounds of herbaceous peony black tea.•Fermentation can significantly improve tea aroma and reduce astringency.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cancer cachexia is a systemic inflammation-driven syndrome, characterized by muscle atrophy and adipose tissue wasting, with progressive weight loss leading to serious impairment of physiological ...function. Extracellular vesicles (EVs) derived from cancer cells play a significant role in adipocyte lipolysis, yet the mechanism remain uneclucidated. In this study, EVs derived from Lewis lung carcinoma (LLC) cells were extracted and characterized. 3T3-L1 and HIB1B adipocytes were cultured with conditioned medium or EVs from LLC, and LLC cells were used to establish a cancer cachexia mouse model. EVs derived from LLC cells were taken up by 3T3-L1 and HIB1B adipocytes, and derived exosomal EIF5A protein-induced lipolysis of adipocytes. High level of EIF5A was expressed in EVs from LLC cells, exosomal EIF5A is linked to lipid metabolism. Elevated expression of EIF5A is associated with shorter overall survival in lung cancer patients. Western blots, glycerol release and Oil red O staining assays were used to evaluate lipolysis of adipocytes. The reduction of lipolysis in 3T3-L1 and HIB1B adipocytes is achieved through silencing EIF5A or treating with pharmacologic inhibitor GC7 in vitro, and suppressing the expression of EIF5A in LLC cells by infected with shRNA or GC7 treatment partly alleviated white and brown adipose tissue lipolysis in vivo. Mechanistically, EIF5A directly binds with G protein-coupled bile acid receptor 1 (GPBAR1) mRNA to promote its translation and then activates cAMP response element binding protein (CREB) signaling pathway to induce lipolysis. This study demonstrates that exosomal EIF5A from LLC cells, with hypusinated EIF5A, has a lipolytic effect on adipocyte and adipose tissues in cancer cachexia model. Exosomal EIF5A could be involved in lipolysis and these findings indicate that a novel regulator and potential target for cachexia treatment.
•Exosomal EIF5A from LLC cells is critical to lipolysis of 3T3-L1 and HIB1B adipocytes in vitro.•EIF5A binds to GPBAR1 mRNA and regulates its translation to activate CREB signaling pathway involves in lipolysis of 3T3-L1 and HIB1B adipocytes.•Inhibition of EIF5A expression in LLC cells attenuates adipocytes lipolysis of cancer cachexia mice.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Six deep-sea proteolytic bacteria taken from Aleutian margin sediments were screened; one of them produced a cold-adapted neutral halophilic protease. These bacteria belong to Pseudoalteromonas spp., ...which were identified by the 16S rDNA sequence. Of the six proteases produced, two were neutral cold-adapted proteases that showed their optimal activity at pH 7-8 and at temperature close to 35 degrees C, and the other four were alkaline proteases that showed their optimal activity at pH 9 and at temperature of 40-45 degrees C. The neutral cold-adapted protease E1 showed its optimal activity at a sodium chloride concentration of 2 M, whereas the activity of the other five proteases decreased at elevated sodium chloride concentrations. Protease E1 was purified to electrophoretic homogeneity and its molecular mass was 34 kDa, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight of protease E1 was determined to be 32,411 Da by mass spectrometric analysis. Phenylmethyl sulfonylfluoride (PMSF) did not inhibit the activity of this protease, whereas it was partially inhibited by ethylenediaminetetra-acetic acid sodium salt (EDTA-Na). De novo amino acid sequencing proved protease E1 to be a novel protein.
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CEKLJ, DOBA, FZAB, GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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