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The development of internal phloem in the Jerusalem cherry, Solanum pseudocapsicum L. (Solanaceae), was studied in young and mature stems. The early presence of primary internal phloem is succeeded by the development of secondary internal phloem from an internal cambium situated between the protoxylem and primary internal phloem. In the second and third visible internodes of the young stem, procambial derivatives begin to differentiate as discrete strands of internal protophloem in a perimedullary position prior to the differentiation of protoxylem and external protophloem. In 6–8 mm diameter stems, sieve elements of the internal phloem become non-conducting, begin to collapse, and undergo obliteration. In 15–20 mm diameter stems internal cambium is initiated from the parenchyma cells situated between the protoxylem and primary internal phloem. The development of internal phloem and an internal cambium in S. pseudocapsicum is compared with that in other taxa. There seems to be a gradual variation in the origin of an internal cambium from either remnants of the procambium or dedifferentiation of peripheral pith cells across dicotyledons with an internal cambium.

Investigating the potential of Phanerochaete chrysosporium to decolourise and degrade two reactive textile dyes (Reactive Yellow MERL and Reactive Red ME4BL) was the main intend of the study. The fungus analysed for its decolourising potential has shown the significant success by removing the colour of tested dyes (10 mg/L concentration) within 11 days of incubation. Supplementing media with different carbon/nitrogen sources proved dextrose and aspargine as efficient decolorizing enhancers, while inoculum size of 1 and 3 (10 mm diameter agar plug) were more supportive for solid and liquid decolourisation respectively. The ligninolytic enzyme production under solid state fermentation involved different agro-industrial wastes, among which wheat straw with 1 mm particle size was responsible for optimum production of manganese peroxidase (607.35 IU/ml), manganese independent peroxidase (539.27 IU/ml) and laccase (263.03 IU/ml). The partially purified enzymes produced by P. chrysosporium was achieved at four different percent saturations i.e. 20, 40, 60 and 80, where 60% saturated fraction produced the maximum 607.35 IU/ml of manganese peroxidase having 52.8 kDa molecular weight. The biodegradation of Reactive Yellow MERL (7-(4-{4-chloro-6-[3-(2-sulfoxy-ethanesulfonyl)-phenylamino]-[1,3,5]triazin-2-ylamino}-2-ureido-phenylazo)-naphthalene-1,3,6-trisulfonic acid) and Reactive Red ME4BL (5-{4-choloro-6-[4-(2-sulfo-ehtanesulfonyl)-phenylamino]-[1,3,5]triazin-2-ylamino}-3-(1,5-disulfo-napthalen-2-ylazo)-4-hydroxy-naphthalena-2,7-disulfonic acid) were studied by FTIR analysis where shifting of peaks confirmed the complete degradation of both the dyes.

Background Total three Pleurotus species (P. ostreatus, P. sapidus, P. florida) was compared for ligninolytic enzyme production grown with Coralene Golden Yellow, Coralene Navy Blue and Coralene Dark Red azo dyes in liquid medium under shaking condition. Results The biodegradation competency varied from species to species and it was found that P. ostreatus, P. sapidus and P. florida to 20 ppm dye concentration shows 88, 92 and 98 % decolorization, respectively for all three dyes. Production pattern of laccase, manganese dependent peroxidase and lignin peroxidase were studied during the growth of the organisms for 10 days. Laccase was found to be the major extracellular ligninolytic enzyme produced by fungus with negligible detection of lignin peroxidases. In all concentration of three dye studied, maximum laccase activity was observed on day 8, for 20 mg/l of dye laccase specific activity was 1–1.58 U/mg in P. ostreatus, 0.5–0.78 U/mg in P. sapidus and 1–1.92 U/mg in P. florida. Different factors (dye concentration, pH, protein and sugar estimation) influencing the ability of Pleurotus species to degrade dyes is documented and degradation was attributed to microbial action irrespective of pH change. HPTLC analysis of samples indicated degradation of dyes into intermediate products. Conclusion Level of ligninolytic enzymes is playing a major role in degradation of dye, which is dependent on time of incubation and species of fungi.

Structural alterations induced in response to degradation by two white rot Basidiomycetes on the secondary xylem of Azadirachta indica (L) Del., was compared. In vitro decay test was employed to investigate the pattern of delignification of Azadirachta wood by Trichoderma harzianum and Chrysosporium asperatum. Wood samples inoculated with both the strains were analyzed for different periods viz. 30, 60, 90 and 120 days after fungal inoculation. Initially there was no appreciable percent weight loss of the wood blocks but later on (after 60 days) it increased rapidly and was found similar for both the strains (43–46% of wood mass). Samples inoculated with both the strains showed dual pattern of degradation i.e. selective delignification in the initial stage followed by simultaneous rot during advance stage of decay. Separation of the cells due to dissolution of middle lamella was the characteristic feature of both strains but in the advanced stage of decay, formation of erosion troughs were conspicuous in all the cell types. Other features such as cell wall thinning, rounded pit erosion, formation of erosion channels and bore holes were also observed frequently. Initially, fungal invasion started through the vessel lumen, followed by all the cell types of the xylem. From the vessels, mycelia entered into the adjacent rays and parenchyma cells through the pits. In advanced stage, degradation was so pronounced that rays were partially or even completely destroyed while many cells including vessels were either deformed or destroyed due to loss of rigidity of their walls. Structural alterations induced in response to C. asperatum and T. harzianum attack is described in details.

The pattern of delignification in Ailanthus excelsa Roxb. wood, naturally infected by Inonotus hispidus (Bull.: Fr.) Karst., was studied by light microscopy. Inonotus hispidus produced a typical pattern of soft rot decay even though it is grouped with white rot basidiomycetes. Fungal hyphae colonised all cell types of the secondary xylem but more damage was observed in xylem fibres. In the early stage, infection commenced on the cell wall corners and middle lamellae of the fibre wall without any pronounced effect on the primary and secondary wall layers. Delignification of fibre wall became apparent when all cell types became completely invaded by fungal hyphae. It started from within the lumina towards the middle lamellae, occurring initially in the immediate vicinity of hyphae growing on the luminal surface by forming an erosion trough. At an advanced stage of decay, localised degradation of lignin, cellulose and hemicellulose resulted in the formation of small cavities within the secondary walls (S2) o...

A locally isolated strain of Trichoderma harzianum was studied for production of xylanase (EC 3.2.1.8) using lignocellulosic substrates for solid-state fermentation. Among the different substrates used, wheat straw produced the highest yields (146 IU/ml). The influence of temperature, pH, moistening agents, moisture level, carbon sources, nitrogen sources, pretreatments and metal ions were evaluated with respect to xylanase production. Highest xylanase production was obtained using wheat straw after 12 days of incubation. Different substrate combination ratios and the effect of particle size were also checked against xylanase production. Maximum xylanase production was observed in a wheat straw/rice straw ratio of 1:1, with a particle size of 0.45–0.5 mm. Media supplementation with xylose as a carbon source in a ratio 1:5 (carbon source/substrate) gave maximum activity (157 IU/ml). Nitrogen supplementations from yeast extract produced xylanase activity of 141 IU/ml. Optimum xylanase production was observe...

Development of gum ducts and chemical nature of occluding material was studied by histological and histochemical methods in the differentiating xylem of Azadirachta indica A.Juss. In response to injury and subsequent fungal infection the stem developed vascular occlusions and gum resin cavities. Fungal hyphae were observed in all the cell types of xylem including vessel elements and associated parenchyma cells. Chemical nature and forms of the occluding material in gum ducts/cavities differed from that of wound exudates. The occluding material was rich in proteins, lipids, polysaccharides, lignin and phenolics while the material exuded from wounds contained only lipids and proteins. The epithelial cells of the gum ducts showed intense staining for nucleic acids, proteins and insoluble polysaccharides as compared to the neighbouring cells. Some of the epithelial cells accumulated phenolics, which were later released into the duct lumen after dissolution of cell walls. Axial parenchyma cells near the cavities/ducts were free from starch while the vessels were plugged with gum-like material and tyloses. On the other hand, xylem parenchyma cells away from the infection site showed heavy accumulation of starch and negligible amounts of proteins and lipids. The boundary layer was characterised by the presence of few vessels and an abundance of axial and ray parenchyma with heavy accumulation of phenolics, particularly a catacholic type of tannin.

Morpho-anatomical features in leaves, stems and unripe fruits of Solanum pseudocapsicum L., Solanaceae, were investigated by histological methods. Anatomically the plant may be characterised by the presence of uniseriate trichomes, anomocytic stomata, calcium oxalate needles in leaves while presence of oval to circular compound starch grains, angular vessels, vertically upright, uni-biseriate rays and intraxylary phloem with differentiation of internal cambium abutting marginal pith cells and protoxylem in transverse view. Development of distinct internal cambium may be considered as a characteristic feature for S. pseudocapsicum. Intraxylary secondary phloem was composed of sieve tube elements, companion cells and axial parenchyma cells.

A potent fungus for amylase production, Chrysosporium asperatum, was isolated from among 30 different cultures obtained from wood samples collected in the Junagadh forest, India. All of the isolated cultures were screened for their ability to produce amylase by submerged fermentation. Among the selected cultures, C. asperatum (Class Euascomycetes; Onygenales; Onygenaceae) gave maximum amylase production. In all of the different media tested, potato starch was found to be a good substrate for production of amylase enzyme at 30 degrees C and pH 5.0. Production of enzyme reached the maximum when a combination of starch and 2% xylose, and organic nitrogen (1% yeast extract) and ammonium sulfate were used as carbon and nitrogen sources, respectively. There was no significant effect of metal ions on enzyme activity. The enzyme was relatively stable at 50 degrees C for 20 min, and no inhibitory effect of Ca+2 ions on amylase production was observed.