Chandrakant S. Karigar

Role of Microbial Enzymes in the Bioremediation of Pollutants: A Review

A large number of enzymes from bacteria, fungi, and plants have been reported to be involved in the biodegradation of toxic organic pollutants. Bioremediation is a cost effective and nature friendly biotechnology that is powered by microbial enzymes. The research activity in this area would contribute towards developing advanced bioprocess technology to reduce the toxicity of the pollutants and also to obtain novel useful substances. The information on the mechanisms of bioremediation-related enzymes such as oxido-reductases and hydrolases have been extensively studied. This review attempts to provide descriptive information on the enzymes from various microorganisms involved in the biodegradation of wide range of pollutants, applications, and suggestions required to overcome the limitations of their efficient use.

Effect of biotic elicitors on the accumulation of bilobalide and ginkgolides in Ginkgo biloba cell cultures

The effect of biotic elicitors on the production of bilobalide and ginkgolides in Ginkgo biloba cell suspension cultures was studied. The treatment of cell cultures with Candida albicans and Staphylococcus aureus as elicitors increased the amounts of bilobalide (BB), ginkgolide A (GA) and ginkgolide B (GB), with slight growth inhibition. The native bacterial elicitor was more effective for secondary metabolite accumulations both in cells and culture medium than autoclaved. However, exposure times of the cells to the elicitors strongly influenced the production of BB, GA and GB. This study suggests that biotic elicitors can regulate the production of BB, GA and GB either directly or indirectly. These results also describe the establishment of optimum conditions that determine the effects of biotic elicitors on secondary metabolism of bilobalides.

ENHANCED PRODUCTION OF TROPANE ALKALOIDS IN SCOPOLIA PARVIFLORA BY INTRODUCING THE PMT (PUTRESCINE N-METHYLTRANSFERASE) GENE

SummaryIn wild-type Scopolia parvilfora (Solanaceae) tissues, only the roots express the enzyme putrescine N-methyltransferase (PMT; EC 2.1.1.53), which is the first specific precursor of the tropane alkaloids. Moreover, the tropanane alkaloid levels were the highest in the root (0.9 mg g−1 on a dry weight basis), followed by the stem and then the leaves. We metabolically engineered S. parviflora by introducing the tobacco pmt gene into its genome by a binary vector system that employs disarmed Agrobacterium rhizogenes. The kanamycin-resistant hairy root lines were shown to bear the pmt gene and to overexpress its mRNA and protein product by at least two-fold, as determined by polymerase chain reaction (PCR) and Northern and Western blottings, respectively. The transgenic lines also showed higher PMT activity and were morphologically aberrant in terms of slower growth and the production of lateral roots. The overexpression of pmt markedly elevated the scopolamine and hyoscyamine levels in the transgenic lines that showed the highest pmt mRNA and PMT protein levels. Thus, overexpression of the upstream regulator of the tropane alkaloid pathway enhanced the biosynthesis of the final product. These observations may be useful in establishing root culture systems that generate large yields of tropane alkaloids.

The Nobel Prize in Chemistry 2004 'Ubiquitous' Quality Control of Life

The Nobel Prize in Chemistry for 2004 is shared by Aaron Ciechanover, Avram Hershko and Irwin Rose, who made fundamental discoveries concerning how cells regulate the breakdown of cellular proteins with extreme specificity. The three biochemists discovered ubiquitin-mediated proteolysis, a process where an enzyme system tags unwanted proteins with many molecules of a small protein called ubiquitin and then sends then to the proteasome where they are broken down.

Enzymatic release of ferulic acid fromIpomoea batatas L. (sweet potato) stem

Ferulic acid is a phenolic compound that serves as a major biosynthetic precursor of vanillin in higher plants. We investigated the ability of the 3 commercial enzymes—Ultraflo L, Viscozyme L, and α-Amylase—to induce the release ferulic acid from theIpomoea batatas L. (sweet potato) stem. The rate of release for ferulic acid was optimal when Ultraflo L (1.0%) was used compared with the other enzymes, whereas Viscozyme L was most effective for the release of vanillic acid and vanillin. Thus, these enzymes may be useful for the large-scale production of ferulic acid and other phenolic compounds from sweet potato stem.

Enhanced production of tropane alkaloids in transgenic Scopolia parviflora hairy root cultures over-expressing putrescine N-methyl transferase (PMT) and hyoscyamine-6β-hydroxylase (H6H)

Scopolia parviflora adventitious roots were metabolically engineered by co-expression of the two gene putrescine N-methyl transferase (PMT) and hyoscyamine-6β-hydroxylase (H6H) cDNAs with the aid of Agrobacterium rhizogenes. The transformed roots developed into morphologically distinct S. parviflora PMT1 (SpPMT1), S. parviflora PMT1 (SpPMT2), and S. parviflora H6H (SpH6H) transgenic hairy root lines. Consequent to the introduction of these key enzyme genes, the production of the alkaloids hyoscyamine and scopolamine was enhanced. Among the transgenic hairy root lines, SpPMT2 line possessed the highest growth index. The treatment of transgenic hairy roots with growth regulators further enhanced the production of scopolamine. Thus, the results suggest that PMT1, PMT2, and H6H genes may not only be involved in the metabolic regulation of alkaloid production but also that these genes may play a role in the root development.

Rapid selection of catechin-rich tea trees (Camellia sinensis) by a colorimetric method

A rapid and efficient colorimetric method based on the use of Fast Blue B-salt (FBB) was established to select catechin-rich tea trees (Camellia sinensis L.). The catechin levels measured by the colorimetric method under optimized reaction conditions correlated closely with estimations by high-performance liquid chromatography (HPLC) analysis. The FBB colorimetric method was successfully used to classify 160 tea trees on the basis of their catechin contents into rich and poor lines. HPLC analysis of the FBB-selected tea tree extracts showed them to contain (−)-epigallocatechin 186 mg/g in tea tree line HR-29, (−)-epicatechin 43.7 mg/g in HR-82, (−)-epigallocatechin gallate 4.32 mg/g in HR-29, and (−)-epicatechin gallate 0.22 mg/g in HR-52. Classification of tea trees from the Hadong region into catechin-rich and -poor trees was independent of the growing season. Thus the FBB colorimetric method could find application as a reliable tool in screening and selection of tea trees on the basis of their catechin content.

Production of Tropane Alkaloids during De-differentiation of Scopolia parviflora Calli

The production of tropane alkaloids during differentiation and de-differentiation of Scopolia parviflora calli was studied. Tropane alkaloid production drastically decreased during calli de-differentiation. Scopolamine (1) production decreased after 10 days of culture, whereas that of hyoscyamine (2) decreased during de-differentiation of root to calli. The production of 1 was enhanced in calli undergoing differentiation to shoot after 60 days of culture, reaching a maximum by 80 days. However, production of hyoscyamine in regenerated plants was lower. The expression level of hyoscyamine 6beta-hydroxylase (H6H), a key biosynthetic enzyme for tropane alkaloids, was significantly increased in 4-week-old calli. This study suggests that the biosynthesis of tropane alkaloids is regulated inversely in de-differentiating Scopolia parviflora calli.

Traditional Indian medicine (TIM) and traditional Korean medicine (TKM): aconstitutional-based concept and comparison

Traditional and complementary medicine (T&CM) plays an integral role in providing health care worldwide. It is based on sound fundamental principles and centuries of practices. This study compared traditional Indian medicine (TIM) and traditional Korean medicine (TKM) basing on data obtained from peer reviewed articles, respective government institutional reports and World Health Organization reports. Despite the fact that TIM and TKM have individual qualities that are unique from each other including different histories of origin, they share a lot in common. Apart from Homeopathy in TIM, both systems are hinged on similar principle of body constitutional-based concept and similar disease diagnosis methods of mainly auscultation, palpation, visual inspection, and interrogation. Similarly, the treatment methods of TIM and TKM follow similar patterns involving use of medicinal herbs, moxibustion, acupuncture, cupping, and manual therapy. Both T&CM are majorly practiced in well-established hospitals by T&CM doctors who have undergone an average of 6–7 years of specialized trainings. However, unlike TIM which has less insurance coverage, the popularity of TKM is majorly due to its wide national insurance coverage. These two medical traditions occupy increasingly greater portion of the global market. However, TIM especially Ayurveda has gained more global recognition than TKM although the emergence of Sasang Constitutional Medicine in TKM is beginning to become more popular. This comparative analysis between TIM and TKM may provide vital and insightful contribution towards constitutional-based concept for further development and future studies in T&CM.

Influence of Nitrogen, Phosphorous, Potassium and Sucrose on the Shoot and Bulb Growth of Allium victorialis var. platyphyllum

Effects of nitrogen (N), phosphorous (P) and potassium (K) on the shoot and bulb growth of wild garlic (Allium victorialis var. platyphyllum) were studied by adopting in vitro culture. These macronutrients influenced the growth of both the shoot and bulb of garlic depending upon their application doses. A minimum of 3% potassium nitrate (KNO3) as a source of nitrogen was found to be critical for shoot elongation while higher concentrations were inhibitory. Garlic bulb growth was profuse on the usual KNO3 strength and sucrose (7%), followed by KNO3 (9.4 mM) supplement. On providing 41.22 mM ammonium nitrate (NH4NO3) as nitrogen source highest shoot growth was observed while 82.45 mM NH4NO3 as a source of nitrogen supported high bulb growth. With regard to potassium a good shoot growth was observed in medium that contained 0.31 mM KH2PO4 and 3% sucrose, while bulb growth was high on 2.5 mM KH2PO4 and 7% sucrose. These experiments may thus direct the development of excellent growth conditions for the commercial production of edible wild garlic.