Structural and Functional Investigation of White Sea Water and Bottom Sediments

Statistical analysis of dynamic indices of biopolymers enzymatic destruction in unstratified and stratified White Sea water has revealed specific properties of protease and amylase activities. We analyzed the component composition and hydrolytic enzymatic activities in the surface layer of the bottom sediments (0–2 cm). The relationship between protease and amylase enzymatic activities in the surface sediments with different content of pelite fraction is discussed.     

Fungi and Macroaggregation in Deep-Sea Sediments

Whereas fungi in terrestrial soils have been well studied, little is known of them in deep-sea sediments. Recent studies have demonstrated the presence of fungal hyphae in such sediments but in low abundance. We present evidence in this study that one of the apparent reasons for the poor detection of fungi in deep-sea sediments is their cryptic presence in macroaggregates. Fungal biomass carbon from different core sections of deep-sea sediments from approximately 5000 m depth in the Central Indian Ocean was estimated based on direct microscopic detection of fungal mycelia. Treatment of sediment samples with ethylenediamine tetra-acetic acid (EDTA) enabled more frequent detection and significantly higher biomass than in samples without such treatment. Treatment with EDTA resulted in detecting various stages of breakdown of aggregates in the sediments, gradually revealing the presence of fungal hyphae within them. Experimental studies of a deep-sea, as well as three terrestrial isolates of fungi, showed that all could grow at 200 bar and 5 degrees C in a nutrient medium and in deep-sea sediment extract. Hyphae of fungi grown in sediment extract under the above conditions showed various stages of accretion of particles around them, leading to the formation of aggregates. Such aggregates showed the presence of humic material, carbohydrate, and proteins. We suggest that fungi in deep-sea sediments may be involved in humic aggregate formation by processes very similar to those in terrestrial sediments. The importance of such a process in carbon sequestration and food web in the deep sea needs to be examined.     

海洋沉积环境来源真菌次生代谢产物的研究

海洋沉积环境复杂多样,微生物往往进化形成与其环境相适应的代谢系统.真菌作为海洋沉积环境中的重要微生物,它们的次生代谢产物结构出新率高、生物活性显著,是开发海洋先导药物的新兴资源.本文综述了1995-2011年间发表的200个海洋沉积环境真菌次生代谢产物,其来源菌株广泛分布在真菌16个属,主要集中在Penicillium属(30％)、Aspergillus属(19％)、Spicaria属(18％)和Trichoderma属(13％);其结构类型包括生物碱类(86个)、萜类(42个)、聚酮类(42个)、肽类(15个)、甾体类(5个)、脑苷脂类(4个)和其他类(6个),活性研究主要集中在细胞毒性和抗菌等方面.     

The Distribution of Microscopic Fungi along Moscow Roads

The distribution of microscopic fungi in soils and surface air along some Moscow roads was studied from 1994 through 2000 at several distances (0, 5, 10, and 20 m) from the roads. Soil fungal complexes in roadside zones with different levels of pollution from automobile engines were found to differ in their composition, species structure, and biomorphology. Relatively far from the roads, the content of fungal mycelium diminished, while that of fungal spores increased. Close to the roads, fungal complexes in soil and surface air were dominated by dark melanin-containing fungi. The microscopic fungal complexes of soil and surface air along the roadsides were similar but differed in the relative abundance of some species.     

Biodegradation of Lignin by White Rot Fungi

A review is presented related to the biochemistry of lignocellulose transformation. The biodegradation of wood constituents is currently understood as a multienzymatic process with the mediation of small molecules; therefore, this review will focus on the roles of these small molecular compounds and radicals working in concert with enzymes. Wood rotting basidiomycetous fungi penetrate wood and lead to more easily metabolized, carbohydrate constituents of the complex. Having a versatile machinery of enzymes, the white rot fungi are able to attack directly the "lignin barrier." They also use a multienzyme system including so-called "feed back" type enzymes, allowing for simultaneous transformation of both lignin and cellulose. These enzymes may function separately or cooperatively.     

Dibenzyl Sulfide Metabolism by White Rot Fungi

Microbial metabolism of organosulfur compounds is of interest in the petroleum industry for in-field viscosity reduction and desulfurization. Here, dibenzyl sulfide (DBS) metabolism in white rot fungi was studied. Trametes trogii UAMH 8156, Trametes hirsuta UAMH 8165, Phanerochaete chrysosporium ATCC 24725, Trametes versicolor IFO 30340 (formerly Coriolus sp.), and Tyromyces palustris IFO 30339 all oxidized DBS to dibenzyl sulfoxide prior to oxidation to dibenzyl sulfone. The cytochrome P-450 inhibitor 1-aminobenzotriazole eliminated dibenzyl sulfoxide oxidation. Laccase activity (0.15 U/ml) was detected in the Trametes cultures, and concentrated culture supernatant and pure laccase catalyzed DBS oxidation to dibenzyl sulfoxide more efficiently in the presence of 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) than in its absence. These data suggest that the first oxidation step is catalyzed by extracellular enzymes but that subsequent metabolism is cytochrome P-450 mediated.     

Species Richness and Adaptation of Marine Fungi from Deep-Subseafloor Sediments

The fungal kingdom is replete with unique adaptive capacities that allow fungi to colonize a wide variety of habitats, ranging from marine habitats to freshwater and terrestrial habitats. The diversity, importance, and ecological roles of marine fungi have recently been highlighted in deep-subsurface sediments using molecular methods. Fungi in the deep-marine subsurface may be specifically adapted to life in the deep biosphere, but this can be demonstrated only using culture-based analyses. In this study, we investigated culturable fungal communities from a record-depth sediment core sampled from the Canterbury Basin (New Zealand) with the aim to reveal endemic or ubiquist adapted isolates playing a significant ecological role(s). About 200 filamentous fungi (68%) and yeasts (32%) were isolated. Fungal isolates were affiliated with the phyla Ascomycota and Basidiomycota, including 21 genera. Screening for genes involved in secondary metabolite synthesis also revealed their bioactive compound synthesis potential. Our results provide evidence that deep-subsurface fungal communities are able to survive, adapt, grow, and interact with other microbial communities and highlight that the deep-sediment habitat is another ecological niche for fungi.     

Laccase Production and Humic Acids Decomposition by Microscopic Soil Fungi

Laccase (para-diphenol:oxygen oxidoreductase, EC 1.10.3.2) is a phenol oxidase widespread in fungi and bacteria. In basidiomycetes, this enzyme is involved in the transformation of lignin and humic substances (HS) in soil. The role of laccases of soil ascomycetes and deuteromycetes in HS degradation is not established, and conditions of the enzyme production have been poorly studied. In the present work soil micromycetes, potential laccase producers, were isolated from typical soils of the forest, steppe, and foreststeppe zones of European Russia by plating on agar media with ABTS (2,2'-azino-bis(3-ethylbenzothiazoline- 6-sulphonic acid, sodium salt)) as the substrate. Their abundance, species composition, conditions of laccase production, and its relation to humic acids (HA) degradation in liquid and solid media were studied. Out of 68 strains isolated, 20 exhibited ABTS oxidation at initial plating on agar media. In pure cultures on agar media, oxidation was less pronounced, but in the presence of HA laccase production by some strains was higher than without HA. Significant and weak extracellular laccase production in liquid medium was observed for Acremonium murorum (Corda) W. Gams Z1710 and Botritis cinerea Pers. ex Fries Z1711, respectively. The level of laccase production by A. murorum was the same without inducers and in the presence of HA, while B. cinerea produced laccase only without inducers. No direct correlation was found between the presence of laccase and/or its activity and ability of the fungi to decolorize (degrade) HA. In liquid media active laccase producer A. murorum caused lower HA decolorization (43%) than B. cinerea (62%) and the fungi lacking extracellular laccase (54–81%). The role of micromycete oxidative systems in HA degradation requires further investigation.     

Biodestruction of Phthalic Acid Esters by White Rot Fungi

Applied Biochemistry and Microbiology - The ability of white rot fungi from different ecophysiological groups (primary wood-destroying saprotroph Trametes hirsuta, secondary wood-destroying...     

Solubilization and Mineralization of Lignin by White Rot Fungi

The white rot fungi Lentinula edodes, Phanerochaete chrysosporium, Pleurotus sajor-caju, Flammulina velutipes, and Schizophyllum commune were grown in liquid media containing ¹⁴C-lignin-labelled wood, and the formation of water-soluble ¹⁴C-labelled products and ¹⁴CO₂, the growth of the fungi, and the activities of extracellular lignin peroxidase, manganese peroxidase, and laccase were measured. Conditions that affect the rate of lignin degradation were imposed, and both long-term (0- to 16-day) and short-term (0- to 72-h) effects on the production of the two types of product and on the activities of the enzymes were monitored. The production of ¹⁴CO₂-labelled products from the aqueous ones was also investigated. The short-term studies showed that the different conditions had different effects on the production of the two products and on the activities of the enzymes. Nitrogen sources inhibited the production of both products by all species when differences in growth could be discounted. Medium pH and manganese affected lignin degradation by the different species differently. With P. chrysosporium, the results were consistent, with lignin peroxidase playing a role in lignin solubilization and manganese peroxidase being important in subsequent CO₂ production.     

不同木质纤维素基质上白腐菌降解特性的研究

通过测定木质素、纤维素、半纤维素和漆酶分泌的变化,研究白腐菌在稻草、木屑、粗纤维素、滤纸、黑液木素基质上的降解特性。结果表明,除黑液木素上白腐菌不能生长外,在前25d,各基质中纤维素、半纤维素和木质素含量呈持续下降趋势,之后,降解速率减少,其中木质素的降解速率大于纤维素和半纤维素的降解速率。漆酶分泌在生长初期呈快速上升趋势,第10d酶活达到最大,第10～20d快速下降,其后基本不变,基质中酶活大小顺序为稻草基质、木屑基质、粗纤维和滤纸基质,显示了木质素存在对漆酶分泌的诱导作用。     

白腐菌选择性降解竹基质中木质纤维素的研究

对竹基质白腐菌选择性降解进行了初步研究。结果表明,菌株B1对竹基质中木质素和半纤维素有明显的降解选择性。降解55 d木质素和半纤维素降解率分别达44.4%和47.1%;降解20 d降解选择性最好,木质素和半纤维素降解率选择系数分别是2.08和1.98。从FTIR图谱中木质纤维素相关谱峰(2 924、1 6351、6011、5101、165、1 045、666/cm等)的明显变化也可以得出相同结论。     

The Process of Microbial Sulfate Reduction in Sediments of the Coastal Zone and Littoral of the Kandalaksha Bay of the White Sea

Microbiological and biogeochemical investigations of the coastal zone and the littoral of the Kandalaksha Bay of the White Sea were carried out. The material for investigations was obtained in the series of expeditions of the Institute of Microbiology, Russian Academy of Sciences, in August 1999, 2000, 2001, and in March 2003. The studies were conducted on the littoral and in the water area of the Kandalaksha Preserve, the Moscow University Belomorsk Biological Station, and the Zoological Institute Biological Station, Russian Academy of Sciences. Sediment sampling on the littoral was carried out in the typical microlandscapes differing in the sediment properties and macrobenthos distribution. The maximal sulfate reduction rate (SRR) was shown for the shallow part of the Chernorechenskaya Bay (up to 2550 g S/(dm³ day)) and in the Bab'ye More Bay (up to 3191 g S/(dm³ day)). During the winter season, at a temperature of –0.5 × 0.5°C, the SRR in the sediments of the Kartesh Bay was 7.9 × 13 g S/(dm³ day). In the widest limits, the SRR values varied in the sediment cores sampled on the littoral. The minimal values (11 g S/(dm³ day)) were obtained in the core samples on the silt–sandy littoral. The littoral finely dispersed sediments rich in organic matter were characterized by high SRR values (524–1413 g S/(dm³ day)). The maximal SRR values were shown for the sediments present within the stretch of decomposing macrophytes, in local pits at the lower littoral waterline, and in the mouth of a freshwater stream (51–159 mg S/(dm³ day)). A sharp difference in the level of H₂S production in the type microlandscapes was shown. The average hydrogen sulfide production in finely dispersed sediments constituted 125 mg S/(m² day); in stormy discharge deposits, 1950 mg S/(m² day); in depressions under stones and in silted pits, 4300 mg S/(m² day). A calculation made with regard to the area of microlandscapes with increased productivity shows that the daily H₂S production per 1 km² of the littoral (August) is 60.8 to 202 kg S/(km² day), while the organic carbon consumption for sulfate reduction per 1 km² of the littoral is 46 to 152 kg C_org/(km² day).     

白腐真菌原生质体制备和再生条件的研究

对影响白腐真菌(5．776)原生质体制备和再生的条件：包括菌龄、水解酶液的种类及浓度、酶解温度、酶解时间、再生培养基的稳渗剂的选择进行了研究。通过单因素比较分析和正交实验得到最适合的白腐真菌原生质体制备和再生条件。结果表明：当菌龄为58h,采用1%纤维素酶和1%蜗牛酶(2：1)混合液,酶解温度30℃,酶解时间180min,用0．7mol/L氯化钠作渗透压稳压剂,白腐真菌(5．776)原生质体的形成数和再生率均比优化前大为提高,原生质体形成量为8．36×10~5个/mL,原生质体再生率为9．12%。     

Microbial Delignification with White Rot Fungi Improves Forage Digestibility

Three wild-type white rot fungi and two cellulase-less mutants developed from Phanerochaete chrysosporium K-3 (formerly Sporotrichum pulverulentum) were tested for their ability to delignify grass cell walls and improve biodegradation by rumen microorganisms. Fungal-treated and control stems of Bermuda grass were analyzed for their content of ester- and ether-linked aromatics by using alkali extraction and gas chromatography, for in vitro dry weight digestion and production of volatile fatty acids in in vitro fermentations with mixed ruminal microorganisms, for loss of lignin and other aromatics from specific cell wall types by using microspectrophotometry, and for structural changes before and after in vitro degradation by rumen microorganisms by using transmission electron microscopy. P. chrysosporium K-3 and Ceriporiopsis subvermispora FP 90031-sp produced the greatest losses in lignin and improved the biodegradation of Bermuda grass over that of untreated control substrate. However, C. subvermispora removed the most lignin and significantly improved biodegradation over all other treatments. Phellinus pini RAB-83-19 and cellulase-less mutants 3113 and 85118 developed from P. chrysosporium K-3 did not improve the biodegradation of Bermuda grass lignocellulose. Results indicated that C. subvermispora extensively removed ester-linked p-coumaric and ferulic acids and also removed the greatest amount of non-ester-linked aromatics from plant cell walls. Microscopic observations further indicated that C. subvermispora removed esters from parenchyma cell walls as well as esters and lignin from the more recalcitrant cell walls (i.e., sclerenchyma and vascular tissues). C. subvermispora improved in vitro digestion and volatile fatty acid production by ruminal microorganisms by about 80%, while dry matter loss due to fungi was about 20% greater than loss in untreated control stems. The chemical and structural studies used identified sites of specific fungal attack and suggested mechanisms whereby improvement occurred.     

Decolorization of Alcohol Distillery Wastewater by Thermotolerant White Rot Fungi

To determine a thermotolerant fungus strain for decolorization of alcohol distillery wastewater (ADW), 38 fungus strains were studied. Capacity for ligninolytic enzyme production was examined at 35 and ⁴³C on agar media containing 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and MnCl₂. At 43°C, four Pycnoporus coccineus strains showed a higher potential for ADW decolorization both on agar media and in liquid media. Immobilized mycelia on polyurethane foam removed about threefold more total phenol than did free mycelia under conditions of shaking at 43°C. Moreover, immobilized mycelia removed nearly 50% more color than did free mycelia.