双孢蘑菇原生质体的制备

为提高制罐质量,目前双孢蘑菇生产要求采用气生型菌株,但它的产量较低。而匍匐型菌株产量虽高,可是质量差。因此,如能选育出具有上述两者优点的既高产又优质的菌株,将有重要的理论与实践意义。由于双孢蘑菇孢子多为自身可育,自然杂交机率低,用原生质体融合的方法是达到此目的的有效手段,原生质体的制备。则是该方法的第一步。

Analysis on Bacterial Community Structure in Mushroom(Agaricus bisporus) Compost Using PCR-DGGE

This study aimed to investigate the bacterial communities in mushroom compost piles composed of rice straw, corn stover, and cow dung. Bacterial com- munities of samples at the beginning of composting, at the end of fermentation phase I and II were collected and analyzed using Polymerase Chain Reaction-De- naturing Gradient Gel Electrophoresis （PCR-DGGE） based on 16S rDNA universal primers from Escherichia coli. A total of 56 different clone sequences were obtained （GenBank accession number： KF630598-KF630653）. They were classified into seven phyla and 42 genera. Dominant microflora during composting belonged to phylum Proteobacteria, Firmicutes, and Actinobacteria, with the dominant genera of Bacillus, Paenibacillus, Thermomonospora, Thermasporomyces, Pseudomonas, and Cellvibrio. Bacterial diversity （Shannon index） analysis showed that bacterial species in com- post pile composed mainly of rice straw continuously increased during composting, while those in compost pile composed mainly of corn stover firstly increased and then reduced. Principal component analysis showed that corn stover compost sam- ples at the end of fermentation phase I and phase II were clustered into one group, suggesting that corn stover composted faster than anticipated. In general, rice straw compost has higher bacterial diversity but longer composting time period, while corn stover compost has lower bacterial diversity but shorter composting time period.

山洞蘑菇管理技术研究

采用荷兰技术,在国内开展山洞内种植双孢蘑菇[Agaricus bisporus(Lauge)Sing]试验,在7 167m2菇床上,采收鲜菇104 490 kg,单位面积产量14.58 kg/m2。全栽培周期92 d。

Microbial Community Structure of Casing Soil During Mushroom Growth

The culturable bacterial population and phospholipid fatty acid （PLFA） profile of casing soil were investigated at different mushroom （Agaricus bisporus） cropping stages. The change in soil bacterial PLFAs was always accompanied by a change in the soil eulturable bacterial population in the first flush. Comparatively higher culturable bacterial population and bacterial PLFAs were found in the casing soil at the primordia formation stage of the first flush. There was a significant increase in the ratio of fungal to bacterial PLFAs during mushroom growth. Multivariate analysis of PLFA data demonstrated that the mushroom cropping stage could considerably affect the microbial community structure of the casing soil. The bacterial population increased significantly from casing soil application to the primordia formation stage of the first flush. Casing soil application resulted in an increase in the ratio of gram-negative bacterial PLFAs to gram-positive bacterial PLFAs, suggesting that some gram-negative bacteria might play an important role in mushroom sporophore initiation.

Immobilization of Agaricus Bisporus Laccase on Ceramic-Chitosan Composite Support and Their Properties:Potential for Oily Wastewater Treatment

Laccase was immobilized on the ceramic-chitosan composite support by using glutaraldehyde as the cross-linking reagent. The immobilization conditions and characterization of the immobilized enzyme were investigated. The immobilization of laccase was successfully realized when 3.0 mL of 1.25 mg/mL of laccase at a pH value of 4.0 reacted with 0.15 g of ceramic-chitosan composite support(CCCS) at 4 ℃ for 24 h. The immobilized enzyme exhibited a maximum activity at pH 3.0. The optimal temperatures for immobilized enzyme were 25 ℃ and 50 ℃. The K_m value of immobilized laccase for ABTS was 66.64 μmol/L at a pH value of 3.0 at 25 ℃. Compared with free laccase, the thermal, operating and storage stability of immobilized laccase was improved after the immobilization.

Mycoremediation of Potentially Toxic Trace Elements--a Biological Tool for Soil Cleanup:A Review

Anthropogenic and geogenic activities release potentially toxic trace elements （PTEs） that impact human health and the envi- ronment. Increasing environmental pollution stresses the need for environmentally friendly remediation technologies. Physico-chemical treatments are effective, but are costly and generate secondary pollution on- or off-site. Phytoremediation is a biological treatment that provides positive results for PTE eradication with few limitations. Mycoremediation, a type of bioremediation to use macrofungi （mushrooms） for PTE extraction from polluted sites, is the best option for soil cleanup. This review highlights the scope, mechanisms, and potentials of mycoremediation. Mushrooms produce a variety of extracellular enzymes that degrade polycyclic aromatic hydro- carbons （PAHs）, polychlorinated biphenyls （PCBs）, pesticides, dyes, and petroleum hydrocarbons into simpler compounds. Cadmium （Cd）, lead （Pb）, mercury （Hg）, chromium （Cr）, copper （Cu）, zinc （Zn）, and iron （Fe） have been effectively extracted by Phellinus badius, Amanita spissa, Lactarius piperatus, Suillus grevillei, Agaricus bisporous, Trieholoma terreum, and Fomes fomentarius, re- spectively. Mycoremediation is affected by environmental and genetic factors, such as pH, substrate, mycelium age, enzyme type, and ecology. The bioaccumulation factor （BAF） can make clear the effectiveness of a mushroom for the extraction of PTEs from the substrate. Higher BAF values of Cd （4.34）, Pb （2.75）, Cu （9）, and Hg （95） have been reported for Amanita muscaria, Hypholoma fasciculare, Russula foetens, and Boletus pinophilus, respectively, demonstrating their effectiveness and suitability for mycoremediation of PTEs.