Fate and Degradation of POP-Hexachlorocyclohexane

Hexachlorocyclohexane (HCH) and its isomers are one of the most frequently detected chlorinated contaminants in the environment. In spite of the ban on technical grade HCH and restricted use of γ -HCH (lindane), its residues have not stopped from entering the environment. Its extensive use in the past, present use of lindane in several countries, unused stockpiles of date-expired HCH from earlier manufacturing, as well as leachates from earlier disposal at dump sites continue to pollute the biosphere. Because HCH is a persistent organic pollution (POP) known to have several toxic and deleterious effects on human health and wildlife, it becomes imperative to remove this substance of serious concern to the global community. A better understanding on the fate and degradation of this POP in the environment will facilitate in drawing measures to mitigate this chemical and bring about bioremediation of already contaminated sites. This review focuses on the fate, contamination levels, abiotic and biotic degradation of HCH isomers, genes and enzymes involved in microbial degradation, and future research needs in this area

Fate and Degradation of POP-Hexachlorocyclohexane

Hexachlorocyclohexane (HCH) and its isomers are one of the most frequently detected chlorinated contaminants in the environment. In spite of the ban on technical grade HCH and restricted use of γ -HCH (lindane), its residues have not stopped from entering the environment. Its extensive use in the past, present use of lindane in several countries, unused stockpiles of date-expired HCH from earlier manufacturing, as well as leachates from earlier disposal at dump sites continue to pollute the biosphere. Because HCH is a persistent organic pollution (POP) known to have several toxic and deleterious effects on human health and wildlife, it becomes imperative to remove this substance of serious concern to the global community. A better understanding on the fate and degradation of this POP in the environment will facilitate in drawing measures to mitigate this chemical and bring about bioremediation of already contaminated sites. This review focuses on the fate, contamination levels, abiotic and biotic degradation of HCH isomers, genes and enzymes involved in microbial degradation, and future research needs in this area

Biodegradation of tech-hexachlorocyclohexane in a upflow anaerobic sludge blanket (UASB) reactor

Biodegradability of technical grade hexachlorocyclohexane (tech-HCH) was studied in an upflow anaerobic sludge blanket reactor (UASB) under continuous mode of operation in concentration range of 100–200 mg/l and constant HRT of 48 h. At steady state operation more than 85% removal of tech-HCH (upto 175 mg/l concentration) and complete disappearance of b-HCH was observed. Kinetic constants in terms of maximum specific tech-HCH utilization rate (k) and half saturation velocity constant (KL) were found to be 11.88 mg/g/day and 8.11 mg/g/day, respectively. The tech-HCH degrading seed preparation, UASB reactor startup and degradation in continuous mode of operation of the reactor is presented in this paper

Response surface optimization for decaffeination and theophylline production by fusarium solani

Coffee processing industries generate caffeine-containing waste that needs to be treated and decaffeinated before being disposed. Five fungal isolates obtained on caffeine-containing mineral media were tested for their ability to utilize caffeine at high concentrations. An isolate identified as Fusarium solani could utilize caffeine as a sole source of carbon and nitrogen up to 5 g/l and could degrade it to an extent of 30–53 % in 120 h. Sucrose that was added as an auxiliary substrate (5 g/l) enhanced the biodecaffeination of caffeine to 88 % in 96 h. The addition of co- substrate (sucrose) not only resulted in higher biodecaffeination efficiency, but also reduced the incubation period from the initial 120 to 96 h. Theophylline and 3-methyl xanthine were obtained as the major metabolites of decaffeination at 96 and 120 h, respectively. Response surface methodology used to optimize the process parameters for maximum biodecaffeination as well as theophylline production showed that a pH of 5.8, temperature of 24 °C and inoculum size of 4.8 × 105 spores/ml have resulted in a complete biodecaffeination of caffeine as well as the production of theophylline with a yield of 33 % (w/w). Results thus show that a viable and sustainable process can be developed for the detoxification of caffeine along with the recovery of theophylline, a commercially important chemical

Chemical Composition and Nutraceutical Potential of Indian Borage ( Plectranthus amboinicus

The stem of Indian borage (Plectranthus amboinicus) was found to be an antioxidant rich fraction as evaluated by in vitro models such as DPPH free radical scavenging, reducing power assay, superoxide anion radical scavenging, and total antioxidant capacity. The extract also exhibited antiplatelet aggregation ability, antibacterial activity, and antiproliferative effect against cancer cell lines: Caco-2, HCT-15, and MCF-7. Phytochemical evaluation of the extract revealed the occurrence of total phenolics (49.91 mg GAE/g extract), total flavonoids (26.6 mg RE/g extract), and condensed tannins (0.7 mg TAE/g extract). Among the major phenolics, rosmarinic acid (6.160 mg/g extract) was predominant, followed by caffeic acid (0.770 mg/g extract), rutin (0.324 mg/g extract), gallic acid (0.260 mg/g extract), quercetin (0.15 mg/g extract), and p-coumaric acid (0.104 mg/g extract). The appreciable biological activity and presence of biomolecules in the methanolic extract of stem indicate its potential application as functional food ingredients and nutraceuticals

Compost from sugar mill pressmud and distillery spent wash for sustainable agriculture

This paper describes the process for rapid composting of sugar mill pressmud and distillery spentwash by using microbial culture. These waste materials are processed to organic manure, a value added produce, which can be used to replenish soil nutrients. Replenishment of soil nutrients is essential since plants utilize them to generate a large amount of crop produce, year after year. Physico-chemical characteristics and the nutritive value of compost generated out of pressmud and distillery effluent have been found to support good plant growth. The product has gained wide utility as an ameliorating agent and as a soil conditioner to replenish soil nutrients for sustainable agriculture. Besides, composting is a suitable method for stabilization of organic wastes which avoids discharge of industrial wastes to land and water ecosystems that may cause pollution. Activated composting through microbial culture and appropriate conditions converts the organic matter of pressmud and spentwash into value added compost. The cumbersome bio-nondegradable portion of these wastes such as lignins, melanoidins and humic acid get converted to humus which is an essential component of soil and further enriches the soil for sustainable crop productivity

Antiaflatoxigenic and Antimicrobial Activities of Schiff Bases of 2‑Hydroxy-4-methoxybenzaldehyde, Cinnamaldehyde, and Similar Aldehydes

2-Hydroxy-4-methoxybenzaldehyde (HMBA) is a nontoxic phenolic flavor from dietary source Decalipus hamiltonii and Hemidesmus indicus. HMBA is an excellent antimicrobial agent with additional antiaflatoxigenic potency. On the other hand, cinnamaldehyde from cinnamon is a widely employed flavor with significant antiaflatoxigenic activity. We have attempted the enhancement of antiaflatoxigenic and antimicrobial properties of HMBA, cinnamaldehyde, and similar molecules via Schiff base formation accomplished from condensation reaction with amino sugar (d-glucamine). HMBA derived Schiff bases exhibited commendable antiaflatoxigenic activity at the concentration 0.1 mg/mL resulting in 9.6 ± 1.9% growth of Aspergillus flavus and subsequent 91.4 ± 3.9% reduction of aflatoxin B₁ with respect to control