Probiotic lactic acid bacterium from <Emphasis Type="Italic">kanjika</Emphasis> as a potential source of vitamin B<Subscript>12</Subscript>: evidence from LC-MS,immunological and microbiological techniques

Vitamin B₁₂ was produced by probiotic Lactobacillus plantarum in submerged fermentation (96 h) with successive anaerobic and aerobic phases of 48 h each to give 13 ng vitamin B₁₂/g dry biomass. Sodium cyanide-mediated cell lysis, followed by benzyl alcohol/chloroform/water extraction, improved the release of intracellular vitamin B₁₂ for analysis. The presence of the K⁺ adduct of cyanocobalamin (m/z of 1394) was established using electron spray ionization–mass spectra; growth of a mutant of Escherichia coli in the presence of cyanocobalamin ascertained its bioavailability.     

Risk assessment of submicron PM-bound hexavalent chromium during wintertime

This study reports health risk assessment of PM₁-bound carcinogenic hexavalent chromium [Cr(VI)] from central part of Indo-Gangetic plain (IGP) (PM₁: particulate matter with aerodynamic diameter ≤1µm). Cr(VI) concentration has been estimated utilizing spectrophotometer with a modified novel method. Average ratio of Cr(VI)/Cr_T was 0.39 ± 0.07 (Cr_T: Total chromium) in the central IGP (Kanpur). Our study reports that mass fraction of Cr(VI) averaging at 0.39 is ～3 times higher than that assumed conventionally [Cr(VI)/Cr_T: 1/7]. Cancer risk assessment has been performed by assessing excess cancer risk (ECR) for the Cr(VI). ECR determined due to Cr(VI) was 57 and 14.3 (in one million) for adults and children, respectively. Our study suggests that risk due to Cr(VI) reported in previous studies were being underestimated by a factor of three. The Cr(VI)/Cr_T average ratio of 0.39 determined in this study was utilized to calculate risk assessment due to Cr(VI) from other locations in the IGP. Owing to large population of India (～125 million), the cancer risk due to Cr(VI) inhalation itself would become very significant. Thus, future research should focus on metal speciation of PM-bound samples from different locations to better constraint the toxicological risk assessment on a regional-to-global scale.     

Fast Fourier infrared spectroscopy to characterize the biochemical composition in diatoms

Diatoms are photosynthetic unicellular microalgae and are nature’s hidden source of several biosynthetic metabolites with their use in biofuel, food and drug industries. They mainly contain various lipids, sterols, isoprenoids and toxins with their use in apoptotic, fertility controlling and cancer drugs. Chemical studies on diatoms are limited due to various limitations such as variation of nutrients, contaminants and change in seasonal factors in the environment. To overcome these limitations, we obtained axenic cultures of 12 fresh-water diatom strains on the 22nd day of inoculation having a dry weight of 1 mg each and performed their Fourier transform infrared (FTIR) study for the detection of functional groups responsible for their chemical moiety. The spectral mapping showed a varied level of polyunsaturated fatty acids, amides, amines, ketone bodies and esters for their applications in various pharmacological, food and biofuel industries in the exponential phase of their growth in f/2 media. The FTIR study of the 12 diatom strains showed various similarities in the form of some common peak patterns ranging from 3000 to 3600 cm^?1 for ν_O–H absorption. The symmetric stretching vibration frequency of Diadesmis confervaceae (V2) type species showed different behaviour than others in the spectral region starting from 1600 to 1700 cm^?1. The absorption between 1500 and 1575 cm^?1 reflects the presence of the –N–H group. Infrared (IR) absorptions falling between 1600 and 1700 cm^?1 reflect the presence of amide’s ν_C=O in all species. Placoneis elginensis (V8) type species showed an additional absorption band which is centred around 1735–1750 cm^?1 which perhaps reflects the presence of ester’s ν_C=O. Diadesmis confervaceae (V2), Nitzschia palea (V4), Placoneis elginensis (V8), Nitzschia palea var. debilis (V6), Nitzschia inconspicua (V10), Gomphonema parvulum (V11) and Sellaphora (V12) showed distinct structural features with important key functionalities that can make them essential drug markers in the pharmaceutical industry.     

Uptake and release of bilirubin by skin

1. Skin epithelium of albino rat, mouse and guinea pig was shown to accumulate bilirubin from a medium containing free or bound bilirubin. 2. The K(m) values for bound bilirubin were 2.22x10(-3), 1.33x10(-3) and 9.5x10(-4)m for rat, mouse and guinea pig respectively and the corresponding K(m) values for free bilirubin were 5.2x10(-4), 4.0x10(-4), 1.8x10(-4)m; the V(max.) values of bound and free bilirubin were unchanged. 3. The uptake showed saturation kinetics. Bound bilirubin was released together with serum proteins. Free bilirubin bound to skin was not released into the medium. 4. Freezing and thawing of skin epithelium did not cause any significant lowering of the uptake of bilirubin but heat-denatured skin epidermis took up only 50% of the bound bilirubin or free bilirubin taken up by control unheated skin epithelium. 5. The uptake of free and bound bilirubin was prevented by HgCl(2) but not by sodium arsenate, NaCN, NaF, cycloheximide, 2,4-dinitrophenol or iodoacetate. 6. Most of the free bilirubin was bound to the lipids or lipoprotein fraction of skin epithelium and could be extracted by solvents. 7. Rat skin showed the highest accumulation and efflux of bilirubin.