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21.
The Hazard analysis and critical control points (HACCP) is a preventive system which seeks to ensure food safety and security. It allows product protection and correction of errors, improves the costs derived from quality defects and reduces the final overcontrol. In this paper, the system is applied to the line of cultivation of mushrooms and other edible cultivated fungi. From all stages of the process, only the reception of covering materials (stage 1) and compost (stage 3), the pre-fruiting and induction (step 6) and the harvest (stage 7) have been considered as critical control point (CCP). The main hazards found were the presence of unauthorized phytosanitary products or above the permitted dose (stages 6 and 7), and the presence of pathogenic bacteria (stages 1 and 3) and/or heavy metals (stage 3). The implementation of this knowledge will allow the self-control of their productions based on the system HACCP to any plant dedicated to mushroom or other edible fungi cultivation.  相似文献   
22.
An extracellular exo-maltohexaohydrolase [EC 3.2.1.98] from a Klebsiella pneumoniae (Aerobacter aerogenes) mutant produced about 40% maltohexaose (G6) from short-chain amylose ( =23). Mostly G6 was produced from maltooligosaccharides larger than G6 by an exo-mechanism action. It also hydrolyzed G6 and shorter maltooligosaccharides to give smaller maltooligosaccharides. Its position specificity of action on G3 through G8 was studied with maltodextrins specifically labeled at the reducing-end glucose unit with 14C. The highest frequency of cleavage was at the second bond from the reducing end in G3 through G6. For G7 and G8, the sixth bond from the nonreducing end of the substrate was cleaved with absolute specificity by the exo-mechanism action.

Kinetic parameters of the exo-maltohexaohydrolase on various substrates were also studied. The Michaelis constant (Km) for short-chain amylose was the smallest among the various substrates examined.

G6 was also formed from G4 by a transfer action of the enzyme, with an action pattern dependent on the substrate concentration.  相似文献   
23.
Several compounds were isolated from a Chinese mushroom, Huangmo, the heat-dried fruiting body of Hohenbuehelia serotina. They were identified as linoleic acid (I), hexadecanoic acid (II), β-sitosterol (IV), benzoic acid (V), D-mannitol (VI), sucrose (VII), and L-rhamnose (VIII). In addition, six acidic substances were identified. (Table I). Also, ethyl linoleate, hexadecanoic acid, and 9,12-octadecadienoic acid (Z-Z) ethyl esters, IV, V, and VI were identified for the first time from this mushroom.  相似文献   
24.
(1) Both glutaminases A and B of Pseudomonas aeruginosa are inactivated by urea and guanidine hydrochloride, and the activities are partially restored by removal of the denaturants, while sodium lauryl sulfate denatured irreversibly the isozymes. (2) Glutaminase A consists of 4 identical subunits (mol. wt, 35,000) and B is composed of one polypeptide chain (mol. wt., 67,000). (3) Glutaminase A, which catalyzes the hydrolysis and also the hydroxylaminolysis of L and D isomers of glutamine and asparagine, does not act on γ-N-substituted glutamine e.g., γ-glutamylhydrazide. Some l- and d-γ-glutamyl derivatives, e.g., l- and d-γ-glutamyl-hydrazide, l- and d-γ-glutamylmethylester, and l-γ-glutamyl-l-alanine are substrates for glutaminase B, which does not catalyze the hydrolysis and hydroxylaminolysis of asparagine. α-Amino adipamic acid and α-amino substituted amino acids are inert for both the isozymes. (4) The acylation step is rate-limiting in the catalytic reactions by both the isozymes.  相似文献   
25.
Polyauxotrophic mutants of Corynebacterium glutamicum which have additional requirements to L-phenylalanine were derived from L-tyrosine producing strains of phenylalanine auxotrophs, C. glutamicum KY 9189 and C. glutamicum KY 10233, and screened for L-tyrosine production. The increase of L-tyrosine production was noted in many auxotrophic mutants derived from both strains. Especially some double auxotrophs which require phenylalanine and purine, phenylalanine and histidine, or phenylalanine and cysteine produced significantly higher amounts of L-tyrosine compared to the parents, A phenylalanine and purine double auxotrophic strain LM–96 produced L-tyrosine at a concentration of 15.1 mg per ml in the medium containing 20% sucrose. L-Tyrosine production by the strain decreased at high concentrations of L-phenylalanine.  相似文献   
26.
Mycena chlorophos, which is primarily distributed in Southeast Asia, is a luminous fungus that emits a bright green light from its pileus for about 2 days at approximately 20°C and high relative humidity. The distribution of bioluminescent tissues in the whole pileus and its sections was heterogeneous. The light intensity in the cap and the upper region of the gill was greater than that in the lower region of the gill. At the microscopic level, the light was predominantly emitted from the membranes of hymenium and basidia cells on the gill. The emission was both cell and region specific. The luminescence system was localized in the cell membrane, and a part of the system was on the cell membrane surface. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
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29.
The objective of the present study was to investigate the effects of fermented oyster mushroom (Pleurotus ostreats) by-production (FOMP) supplementation on the growth performance, blood parameters, carcass traits and meat quality in finishing Berkshire pigs. FOMP was made by mixing oyster mushroom by-production with rice bran and barley bran and this mixture was fermented for 60 days. The experimental diets were 0, 3, 5 and 7% of FOMP added to C, T1, T2 and T3 in the basis diet for 7 weeks. Average daily gain (kg/day) was higher in C and T1 than in T2 and T3 ( P < 0.05). Average daily feed intake (kg/day) and feed conversion increased by the addition of FOMP ( P < 0.05). Total cholesterol and high-density lipoprotein cholesterol were higher in T3 than other treatments ( P < 0.05). Carcass weight (kg) was higher in C and T1 than in T2 and T3 ( P < 0.05). Dressing (%) was higher in C than in T3 ( P < 0.05). Crude protein was lower in T3 than in other treatments ( P < 0.05). Crude fat was higher in T2 and T3 than in C ( P < 0.05). pH24 was higher in C than in other treatments ( P < 0.05). Cooking loss (%) was higher in T1 than T2 ( P < 0.05). Water-holding capacity (%) was higher in C than in T1 ( P < 0.05). In meat colour, CIE a* was lower by the addition of FOMP ( P < 0.05). CIE b* was higher in C than in other treatments ( P < 0.05). In backfat colour, CIE L* was lower in T3 than other treatments ( P < 0.05). CIE b* was lower by addition of FOMP ( P < 0.05). Palmitoleic and oleic acid were higher in T3 than in other treatments ( P < 0.05). Linoleic and arachidonic acids were higher in T2 than in other treatments ( P < 0.05). The results indicate that 3% of FOMP affected the growth performance, carcass traits, meat quality and fatty acid in contrast to addition of 5% of FOMP for Berkshire pigs during the finishing period.  相似文献   
30.
Since the 1970s, human subjects that have undergone corpus callosotomy have provided important insights into neural mechanisms of perception, memory, and cognition. The ability to test the function of each hemisphere independently of the other offers unique advantages for investigating systems that are thought to underlie cognition. However, such approaches have been limited to mammals. Here we describe comparable experiments on an insect brain to demonstrate learning‐associated changes within one brain hemisphere. After training one half of their bisected brains, cockroaches learn to extend the antenna supplying that brain hemisphere towards an illuminated diode after this has been paired with an odor stimulus. The antenna supplying the naïve hemisphere shows no response. Cockroaches retain this ability for up to 24 h, during which, shortly after training, the mushroom body of the trained hemisphere alone undergoes specific post‐translational alterations of microglomerular synaptic complexes in its calyces. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007.  相似文献   
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