Changes in Proteins and RNA during Storage of Curcuma Longa L. Rhizome

Changes in RNA and protein contents, and protein profiles were studied in the rhizomes of turmeric (Curcuma longa L.) from the day of harvest to the commencement of sprouting. Protein and RNA contents increased gradually in the initial stages and rapidly in the final stages of storage period. SDS-PAGE analysis of storage proteins revealed synthesis of 56, 52 and 47 kDa proteins during the later stages of storage with concomitant disintegration of 23 and 18 kDa proteins.     

Differential responses ofAzolla microphylla Kaulf andAzolla filiculoides Lam. to lead nitrate

The aquatic fernAzolla is used as a green manure for rice production systems in warm temperate and tropical regions throughout the world. We used lead nitrate in nutrient media to assess the tolerance/response of twoAzolla microphylla andAzolla filiculoides to heavy metals. While both species showed negative responses in growth with an increase in lead concentrations, They were distinctly different in their tolerance for higher concentration of the heavy metal. This was apparent in their growth and biochemical characteristics. Amicrophylla was more tolerant of the higher concentrations of lead nitrate (25 and 50 ppm), whereasA. filiculoides had a higher rate of lead uptake.     

Comparative studies on lignin and polycyclic aromatic hydrocarbons degradation by basidiomycetes fungi

A total of 130 wild basidiomycetes fungi were collected and identified. The polycyclic aromatic hydrocarbons (PAHs) degradation by the potential Phellinus sp., Polyporus sulphureus (in liquid state fermentation (LSF), solid state fermentation (SSF), in soil) and lignin biodegradation were compared with those of a bacterial isolate and their corresponding cocultures. The PAHs degradation was higher in LSF and the efficiency of the organisms declined in SSF and in soil treatment. Phellinus sp. showed better degradation in SSF and in soil. Bacillus pumilus showed higher degradation in LSF. B. pumilus was seen to have lower lignin degradation than the fungal cultures and the cocultures could not enhance the degradation. Phellinus sp. which had higher PAHs and lignin degradation showed higher biosurfactant production than other organism. Manganese peroxidase (MnP) was the predominant enzyme in Phellinus sp. while lignin peroxidase (Lip) was predominant in P. sulphureus.     

Changes in Pigment Composition and Photosynthetic Activity of Aquatic Fern (Azolla Microphylla Kaulf.) Exposed to Low Doses of UV-C (254 nm) Radiation

Changes in the content of pigments and rate of photosynthesis in Azolla microphylla Kaulf. fronds were measured during growth under solar and ultraviolet-C (UV-C) supplemented solar radiation. Maximum content of total chlorophyll (Chl) was observed on the 13^th day (termination of the experiment) of treatment in both control and treated plants. The treated plants had significantly lower total Chl and carotenoid contents than the control plants during the 1^st day of growth. After the 4^th day of exposure to UV-C supplemented solar radiation, the Chl and carotenoids accumulation increased in treated plants, so that the pigment concentration in the treated fronds was nearer to the control values after the 13^th day of treatment. Significant increase in UV absorbing pigments, anthocyanins, and flavonoids was observed at the 13^th day of treatment. In spite of the roughly similar photosynthetic pigment concentration, the photosynthetic activity measured as the rate of electron transport at photosystem 2 was only 65 % of the control values after 13 d of UV-C exposure. This revised version was published online in June 2006 with corrections to the Cover Date.     

Microbial production of poly-β-hydroxybutyrate by marine microbes isolated from various marine environments

Considering the industrial interest of Poly-β-hydroxybutyrate (PHB), bacteria isolated from the various marine arenas were screened for their ability to accumulate PHB and were compared with Wausteria eutropha (MTCC-1285). Among the 42 isolates, four strains showed the accumulation of PHB. The maximum PHB producer Vibrio sp. (MK4) was further studied in detail. To increase the productivity, steps were taken to evaluate the effect of carbon sources, nitrogen sources, pH and sodium chloride concentration on PHB productivity by MK4. The optimized conditions were further used for the batch fermentation over a period of 72 h. Significantly higher maximum biomass of 9.1 g/L with a PHB content of 4.223 g/L was obtained in a laboratory-scale bioreactor at 64 h, thus giving a productivity of 0.065 g/L/h. The extracted polymer was compared with the authentic PHB and was confirmed to be PHB using FTIR analysis and ¹H NMR analysis. Thus, the study highlights the potential of the use of Vibrio sp (MK4) in the commercial production of PHB.     

Differential response ofAzolla microphylla kaulf. andAzolla filiculoides Lam. to sodium fluoride

We assessed the differential response ofAzolla microphylla andAzolla filiculoides to fluoride stress by growing them in culture media containing 1 to 50 ppm sodium fluoride (NaF).A microphylla had a higher total chlorophyll content thanA. filiculoides. Both species showed gradual decreases in protein content as the concentration of NaF increased.A. microphylla accumulated less proline thanA. filiculoides when more NaF was added to the culture medium. For all concentrations tested, the amount of residual fluoride in the nutrient media that supportedA. microphylla was higher than in the nutrient media used for growingA. filiculoides.     

Effects of Enhanced Ultraviolet-B (280–320 nm) Radiation on Growth and Photosynthetic Activities in Aquatic Fern Azolla Microphylla Kaulf

The effects of enhanced UV-B radiation on growth and photosynthetic activities were investigated in fronds of the aquatic fern Azolla microphylla Kaulf. The fronds were exposed to UV-B radiation intermittently once in 3 d during 12 d. Biomass and relative growth rate of UV-B treated Azolla plants and the heterocyst frequency of the UV-B treated symbiont decreased resulting in an increase in doubling time over the control. The doubling time was 3.08 d for control and 3.35 d for UV-B irradiated plants. Chl and carotenoid contents per unit fresh mass and photosystem 2 (PS2) activity also decreased under UV-B treatment. Measurements of photosynthetic activity in terms of fluorescence kinetics and PS2 mediated O₂ evolution showed that the aquatic fern Azolla is sensitive to UV-B damage.