Evaluation of the potential of cassava-based residues for biofuels production

Cassava is the third significant source of calories after rice and maize in tropical countries. The annual production of cassava crop is approximately 550 million metric tons (MMT) which generates about 350 MMT of cassava solid residues, including peel, bagasse, stem, rhizome, and leaves. Cassava peel, bagasse, stem, and rhizome can be exploited for solid, liquid and gaseous biofuels production. Biofuels production from cassava starch started in the 1970s and researchers are now extensively studying cassava residues like peel, bagasse, stem, rhizome, and leaves to unravel their applications in biofuels production. However, there are technical and economic challenges to overcome the problems existing in the production of biofuels from cassava-based residues. This review provides a comprehensive summary of the techniques used for biofuels production from various cassava-based residues.     

Development of novel α-chitin/nanobioactive glass ceramic composite scaffolds for tissue engineering applications

Bioactive glass ceramic nanoparticles (nBGC) were prepared by sol–gel technique. The novel chitin/nBGC composite scaffolds were prepared using chitin gel with nBGC by lyophilization technique. The prepared nBGC and composite scaffolds were characterized using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Fourier Transformed Infrared Spectroscopy (FT-IR) and X-ray diffraction (XRD). The composite scaffolds showed adequate porosity where the nBGC nanoparticles were homogenously distributed on the pore walls. The swelling, density, degradation and in vitro biomineralization capability of the composite scaffolds were also evaluated. The developed composite scaffolds showed adequate swelling and degradation properties along with its ability to become bioactive. Cytocompatability of the scaffolds was assessed using MTT assay, direct contact test and cell attachment studies. Results indicated no sign of toxicity and cells found to be attached to the pore walls offered by the scaffolds. These results suggested that the developed composite scaffold possess the prerequisites for tissue engineering scaffolds and it can be used for tissue engineering applications.     

Betulin inhibits cariogenic properties of <Emphasis Type="Italic">Streptococcus mutans</Emphasis> by targeting <Emphasis Type="Italic">vicRK</Emphasis> and <Emphasis Type="Italic">gtf</Emphasis> genes

Streptococcus mutans, a multivirulent pathogen is considered the primary etiological agent in dental caries. Development of antibiotic resistance in the pathogen has created a need for novel antagonistic agents which can control the virulence of the organism and reduce resistance development. The present study demonstrates the in vitro anti-virulence potential of betulin (lup-20(29)-ene-3β,28-diol), an abundantly available plant triterpenoid against S. mutans UA159. Betulin exhibited significant dose dependent antibiofilm activity without affecting bacterial viability. At 240 µg/ml (biofilm inhibitory concentration), betulin inhibited biofilm formation and adherence to smooth glass surfaces by 93 and 71 % respectively. It reduced water insoluble glucan synthesis by 89 %, in conjunction with down regulation of gtfBC genes. Microscopic analysis confirmed the disruption in biofilm architecture and decreased exopolysaccharide production. Acidogenicity and aciduricity, key virulence factors responsible for carious lesions, were also notably affected. The induced auto-aggregation of cells upon treatment could be due to the down regulation of vicK. Results of gene expression analysis demonstrated significant down-regulation of virulence genes upon betulin treatment. Furthermore, the nontoxic effect of betulin on peripheral blood mononuclear cells even after 72 h treatment makes it a strong candidate for assessing its suitability to be used as a therapeutic agent.     

Fatty acid regulation of protein kinase C isoforms in prostate cancer cells

Polyunsaturated fatty acids influence the aetiology of prostate cancer. Their effects on cellular mechanisms regulating prostate tumorigenesis are unclear. Using prostate cancer cells (LNCaP), we determined effects of n-9-OA, n-6-LA, and n-3-EPA on total PKC and its isoforms in relation to cell proliferation and PSA production. PKC-alpha, delta, gamma, iota, mu, and zeta were present in LNCaP cells; PKC-beta, epsilon, eta, and theta isoforms were not. PKC-alpha was detected only in cytosol; PKC-delta, iota, gamma, and mu were present in cytosol and in membranes. Fatty acids increased cell proliferation, total PKC activity and elicited pro-proliferative effects on specific PKC isoforms (PKC-delta and -iota). EPA and LA increased total PKC activity and reduced membrane-abundance of PKC-delta. OA reduced cytosolic and membrane PKC-delta. Only EPA reduced PKC-gamma membrane abundance. Fatty acids enhanced cytosolic PKC-iota abundance but only EPA and to a lesser extent LA increased its membrane content. Changes in PKC-delta, -iota, and -gamma did not affect PSA production.     

Absolute versus per unit body length speed of prey as an estimator of vulnerability to predation

To study whether absolute (m/s) or relative (body lengths/s) speed should be used to compare the vulnerability of differently sized animals, we developed a simple computer simulation. Human 'predators' were asked to 'catch' (mouse-click) prey of different sizes, moving at different speeds across a computer screen. Using the simulation, a prey's chances of escaping predation depended on its speed (faster prey were more difficult to catch than slower prey of the same body size), but also on its size (larger prey were easier to catch than smaller prey at the same speed). Catching time, the time needed to catch a prey, also depended on both prey speed and prey size. Relative prey speed (body lengths/s or body surface/s) was a better predictor of catching time than was absolute prey speed (m/s). Our experiment demonstrates that, in contrast to earlier assertions, per unit body length speed of prey may be more 'ecologically relevant' than absolute speed. Copyright 1998 The Association for the Study of Animal Behaviour.     

Molecular cloning of growth hormone encoding cDNA of Indian major carps by a modified rapid amplification of cDNA ends strategy

A modified rapid amplification of cDNA ends (RACE) strategy has been developed for cloning highly conserved cDNA sequences. Using this modified method, the growth hormone (GH) encoding cDNA sequences ofLabeo rohita, Cirrhina mrigala andCatla catla have been cloned, characterized and overexpressed inEscherichia coli. These sequences show 96–98% homology to each other and are about 85% homologous to that of common carp. Besides, an attempt has been made for the first time to describe a 3-D model of the fish GH protein.     

Effect on growth and reproduction of hormone immersed and masculinized fighting fish Betta splendens

To produce all-male progenies in the fighting fish, Betta splendens, six groups of fry were subjected to discrete immersion treatment at different 17alpha-methyltestosterone (MT) doses (viz. 100, 200, 500, 700, 900, and 1,000 microg/l) for a constant duration (3 hr/day) and frequency (second, fifth, and eighth day after hatching). The treatment at 900 microg/l led to 98% masculinization and 71% survival at sexual maturity. Treated groups, which showed significant deviation from the 1:1 sex ratio, were classified into two different series: S1 and S2. The groups that showed nearly cent-percent masculinization were classified as S1, and the other groups were classified as S2. The S1 males showed remarkably slower growth and attained 3.5 cm total length compared to 6.0 cm attained by a normal male. The S2 males attained 5.4 cm total length. Apart from these morphological defects, both S1 and S2 males suffered functional (decreased sperm count and sperm motility) and behavioral defects (incomplete embracing during mating) in their reproductive ability, leading to approximately 50% and 30% reduction in fecundity per mating, respectively. The cumulative fecundity loss suffered by the S1 male during its active reproductive phase is discussed. When normal and sex-reversed males were presented, a female preferred the former. Progeny testing of the sex-reversed males showed the occurrence of 12.75% males, indicating the possible role of autosomal genes in the sex determination mechanism of this species. Discrete immersion treatment at optimal/super-optimal doses ensured not only a higher percentage of masculinization, but also a higher frequency of homogametic males (XX).     

Neuroprotective evaluation of standardized extract of Centella asciatica in monosodium glutamate treated rats

The effect of chloroform: methanolic (80:20) extract of C. asiatica (CA; 100 and 200 mg/kg), was evaluated on the course of free radical generation and excitotoxicity in monosodiumglutamate (MSG) treated female Sprague Dawley rats. The extract showed significant improvement in catalase, super oxide desmutase and lipid peroxides levels in hippocampus and striatum regions. Glutathione level was not altered with CA treatment. Similar observation was made with dextromethorphan. The general behavior, locomotor activity and CAl a region of the hippocampus was significantly protected by CA indicating neuroprotective effect of CA in MSG induced excitotoxic condition. Hence it can be concluded that CA protected MSG induced neurodegeneration attributed to its antioxidant and behavioural properties. This activity of CA can be explored in epilepsy, stroke and other degenerative conditions in which the role of glutamate is known to play vital role in the pathogenesis.