Unstandardized UV-C dose used for killing harmful cyanobacteria may instead initiate accelerated growth in the target organisms.

Although UV-C radiation has been in use for killing unwanted cyanobacteria, experiments with lower doses of UV-C radiation instead showed induction of growth related parameters and enhanced biomass production in the cyanobacterium Nostoc muscorum Meg1. When the cyanobacterial cultures were exposed to UV-C radiation of varying doses (6, 12 and 18 mJ/cm), concentrations of various photo-absorbing pigments, RuBisCO and D1 protein of PSII; activities of oxygen evolving complex, nitrogenase and glutamine synthetase were significantly increased upon 6 and 12 mJ/cm UV-C radiation exposures. Resulting higher photosynthetic performance was evident from the augmentation in carbohydrate content by ∼49% under single exposure to 6 mJ/cm UV-C by fifteenth day.

Hydrocarbon degradation potential and competitive persistence of hydrocarbonoclastic bacterium Acinetobacter pittii strain ABC.

Acinetobacter pittii strain ABC was isolated from oily sludge sediments and characterized with regard to utilization/degradation of hydrocarbons and competitive persistence in hydrocarbon-amended media. The isolate grew in both aliphatic- and aromatic hydrocarbon-amended Bushnell-Haas medium (BHM). When incubated in 1% (v/v) Assam crude oil-amended BHM for 5 and 10 days, this strain was able to degrade 88% and 99.

Dose dependent variance in UV-C radiation induced effects on carbon and nitrogen metabolism in the cyanobacterium Nostoc muscorum Meg1.

With the intention of getting an insight into the differential effect of UV-C radiation on the N-fixing heterocystous cyanobacterium Nostoc muscorum Meg1, various aspects of carbon and nitrogen metabolism was evaluated in the organism. Exposure to different doses of UV-C (6, 12, 18 and 24 mJ/cm) showed that among various photo-absorbing pigments, phycobiliproteins were most sensitive. Oxygen evolving complex (OEC) activity measured as net oxygen evolution rate decreased by 63% upon 24 mJ/cm exposure.

Zn sequestration by Nostoc muscorum: study of thermodynamics, equilibrium isotherms, and biosorption parameters for the metal.

Microbial biosorption has evolved as an effective strategy for heavy metal removal from contaminated waters. The common cyanobacterium Nostoc muscorum isolated from the banks of a polluted river in Meghalaya, India, was tested for its potential to remove Zn from aqueous solutions. Energy-dispersive X-ray (EDX) study verified Zn binding on the cyanobacterial biomass, and FTIR analysis revealed many negatively charged functional groups (hydroxyl, carbonyl, alcohol, amine, phosphoryl, sulfhydryl, and carboxyl) on the cell surface that aided in metal binding.

Cyanobacteria: A Precious Bio-resource in Agriculture, Ecosystem, and Environmental Sustainability.

Keeping in view, the challenges concerning agro-ecosystem and environment, the recent developments in biotechnology offers a more reliable approach to address the food security for future generations and also resolve the complex environmental problems. Several unique features of cyanobacteria such as oxygenic photosynthesis, high biomass yield, growth on non-arable lands and a wide variety of water sources (contaminated and polluted waters), generation of useful by-products and bio-fuels, enhancing the soil fertility and reducing green house gas emissions, have collectively offered these bio-agents as the precious bio-resource for sustainable development. Cyanobacterial biomass is the effective bio-fertilizer source to improve soil physico-chemical characteristics such as water-holding capacity and mineral nutrient status of the degraded lands.

A common transport system for methionine, L-methionine-DL-sulfoximine (MSX), and phosphinothricin (PPT) in the diazotrophic cyanobacterium Nostoc muscorum.

We present evidence, for the first time, of the occurrence of a transport system common for amino acid methionine, and methionine/glutamate analogues L-methionine-DL-sulfoximine (MSX) and phosphinothricin (PPT) in cyanobacterium Nostoc muscorum. Methionine, which is toxic to cyanobacterium, enhanced its nitrogenase activity at lower concentrations. The cyanobacterium showed a biphasic pattern of methionine uptake activity that was competitively inhibited by the amino acids alanine, isoleucine, leucine, phenylalanine, proline, valine, glutamine, and asparagine.

Isolation and characterization of a Mastigocladus species capable of growth, N(2)-fixation and N-assimilation at elevated temperature.

A Mastigocladus species was isolated from the hot spring of Jakrem (Meghalaya) India. Uptake and utilization of nitrate, nitrite, ammonium and amino acids (glutamine, asparagine, arginine, alanine) were studied in this cyanobacterium grown at different temperatures (25°C, 45°C). There was 2-3 fold increase in the heterocyst formation and nitrogenase activity in N-free medium at higher temperature (45°C).

Isolation and characterization of a chlorate-resistant mutant (Clo- R) of the symbiotic cyanobacterium Nostoc ANTH: heterocyst formation and N(2)-fixation in the presence of nitrate, and evidence for separate nitrate and nitrite transport systems.

Nostoc ANTH is a filamentous, heterocystous cyanobacterium capable of N(2)-fixation in the absence of combined nitrogen. A chlorate-resistant mutant (Clo- R) of Nostoc ANTH was isolated that differentiates heterocysts and fixes N(2) in the presence of nitrate, but not in the presence of nitrite or ammonium. The mutant lacks nitrate uptake and thereby also lacks induction of nitrate reductase activity by nitrate.

Nitrogen nutrition in the cyanobacterium Nostoc ANTH, a symbiotic isolate from Anthoceros: uptake and assimilation of inorganic-n and amino acids.

Amino acid uptake and utilization of various nitrogen sources (amino acids, nitrite, nitrate and ammonia) were studied in Nostoc ANTH and i ts mu tant (Het(-)Nif(-)) isolate defective in heterocyst formation and N2-fixation. Both parent and its mutant grew at the expense of glutamine, asparagine and arginine as a source of fixed-nitrogen. Growth was better in glutamine-and asparagine-media as compared to that in arginine media.