Production of inulinase from Kluyveromyces marxianus using Dahlia tuber extract

Various carbon sources were evaluated for production of inulinase by yeast, Kluyveromyces marxianus MTCC 3995. Highest inulinase activity was observed with Dahlia extract (25.3 nkat mL-1) as carbon source. The enzyme activity was 1.4 folds higher than that observed in media containing pure chicory inulin (17.8 nkat mL-1). The yeast showed good growth on a simple medium containing dahlia extract (20% w/v) and yeast extract (2%w/v) as carbon and nitrogen source respectively, in 96 h. at 28°C and 120 rpm. Lowest inulinase yield (4.8 nkat mL-1) was seen in the medium containing glucose as C-source. Although varied inulinase levels were noticed on different C- sources, Inulinase: Sucrase (I/S) ratios were noticed to be similar. Among various protein sources tested, yeast extract was found to be the best source followed by beef extract (17.9 nkat mL-1) and peptone (13.8 nkat mL-1). The enzyme was optimally active at pH (4.0) and 50°C. TLC analysis of end product revealed that inulinase hydrolyzed inulin exclusively into fructose. Results suggest that the dahlia extract induced exoinulinase synthesis in Kluyveromyces marxianus and can be utilized as a potential substrate for inulinase production.

Feather degradation by strains of Bacillus isolated from decomposing feathers

Feather waste is generated in large amounts as a by-product of commercial poultry processing. This residue is almost pure keratin, which is not easily degradable by common proteolytic enzymes. Eight strains of Bacillus, isolated from decomposing feathers were tested for the hydrolysis of feather wastes in the laboratory. Among these strains, Bacillus cereus KB043 was the best feather degrading organism when grown on basal medium containing 1 percent hen feather as sole source of carbon and nitrogen. It caused 78.16 ± 0.4 percent degradation with a significant release of soluble protein (1206.15 ± 14.7 µg mL-1) and cysteine (20.63 ± 0.4 µg mL-1) in the cultivation fluid. The strain also showed the highest level of keratinase activity (39.10 ± 0.4 U mL-1). These data indicates that the Bacillus cereus KB043 could be useful in management of poultry wastes.

Production and partial characterization of collagenase of Streptomyces exfoliatus CFS 1068 using poultry feather.

Streptomyces exfoliatus CFS 1068, an isolate of cultivated field soil, produced maximum collagenase activity (58.19 ± 0.83 U ml-1min-1) in 5 days when soybean meal and starch were used as nitrogen and carbon sources, respectively at pH 7 and 30°C in shake cultures (150 rpm). Production of collagenase was higher (40.43± 0.63 U ml-1min-1) when poultry feathers were used as nitrogen source. Thus, the strain was found to be of biotechnological importance. The purified enzyme showed 30.34 fold increase in collagenase activity and was stable at 70°C for 1h. The enzyme was found to be of serine type.

Isolation, characterization and antifungal activity of Streptomyces sampsonii GS 1322.

For new antifungal antibiotics from actinomycetes, a strain of Streptomyces GS 1322 was isolated from a sample of garden soil. The strain was found to possess antagonistic activity against four fungi i.e., Candida albicans, Aspergillus niger, Microsporum gypseum and Trichophyton sp. The strain was identified as Streptomyces sampsonii and the antifungal compound produced by it was found to be the heptaene group of polyene antibiotics.

Cortical activation during finger tapping in thyroid dysfunction: a functional magnetic resonance imaging study.

Thyroid dysfunction is associated with attention deficit and impairment of the motor system (muscle weakness and fatigue). This paper investigates possible motor function deficit in thyroid patients,compared to the controls. Functional MRI studies (fMRI)were carried out in five hypo and five hyperthyroid patients and six healthy volunteers. Whole brain imaging was performed using echo planar imaging (EPI)technique, on a 1.5T whole body MR system (Siemens Magnetom Vision). The task paradigm consisted of 8 cycles of active and reference phases of 6 measurements each, with right index finger tapping at a rate of 120 taps/min. Post-processing was performed using statistical parametric mapping on a voxel-by-voxel basis using SPM99. Clusters of activation were found in the contralateral hemisphere in primary somatomotor area (M1), supplementary motor area (SMA), somatosensory,auditory receptive and integration areas, inferior temporal lobe, thalamus and cerebellum. Increased clusters of activation were observed in M1 in thyroid subjects as compared to controls and with bilateral activation of the primary motor cortex in two hyperthyroid patients. The results are explained in terms of increased functional demands in thyroid patients compared to volunteers for the execution of the same task.

Production of heptaene antifungal antibiotic by Streptomyces purpeofuscus CM 1261.

A strain of Streptomyces purpeofuscus CM 1261 isolated from a sample of compost collected locally was found to possess strong antagonistic activity against 4 human pathogenic fungi i.e., Candida albicans, Aspergillus niger, Microsporum gypseum and Trichophyton sp. The active antifungal compound produced by it was found to be a heptaene group of polyene antifungal antibiotic.

Production of industrially important enzymes by some actinomycetes producing antifungal compounds.

Seventeen strains of actinomycetes antagonistic to yeast and moulds have been tested for their ability to produce amylase, lipase, gelatinase and caseinase using solid media containing starch, Tween-20, gelatin and skimmed milk, respectively, Enzyme producing potential of test strains is expressed in ternis of relative enzyme activity (REA). Actinomycetes strain Streptomyces somaliensis GS 1242 and Streptomyces sampsonii GS 1322 showed higher amylase production (REA 6.5) while maximum lipase activity was noted in Streptomyces strain SAP 1089 (REA 7.0). Gelatinase activity was noted higher is S. sampsonii GS 1322 (REA 9.6) and S. somaliensis GS 1242 (REA 8.8). Enzyme producing potential of these strains has been discussed in terms of their industrial significance.

Antifungal activity of some actinomycetes isolated from various habitats.

A total of 287 actinomycetes were isolated from 79 samples collected from five different habitats i.e., cultivated field soil (CFS), garden soil (GS), compost (CM), decaying organic matter (DOM) and stored agricultural products (SAP) of different localities of Sagar, Madhya Pradesh (23 degrees 50 degrees N latitude and 78 degrees 40 degrees E longitude). These were screened for antagonistic activity against Candida albicans, Aspergillus niger, Microsporum gypseun and Trichophyton sp. using 'Cross streak method'. Out of these, a total of 166 isolates were found antagonistic to Candida albicans, while 164, 134 and 132 actinomycetes showed antagonistic properties against A. niger, M. gypseum and Trichophyton sp., repectively. A total of 17 isolates showed very strong anticandidal activity causing total inhibition in the growth of C. albicans and hence, distribution of isolated test actinomycetes in different habitats and the cultural and antagonistic properties of selected 17 promising strains are reported here.

In vitro evaluation of sulfadrugs against fungi causing otomycosis.

The efficacy of four sulfadrugs i.e., sulfadiazine, sulfamethoxazole, sulfaguanidine and sulfamoxole were taken in different doses (500, 1000, 1500, 2000 and 2500 ppm) to test their effectiveness against five pathogenic organisms for the control of mycelial growth and sporulation. Amongst the drugs tested sulfamethoxazole seems to be most effective against most of the test fungi showing 96.78, 90.53, 86.62, 54.16 and 43.91 percent inhibition in mycelial growth of P. nigricans, A. flavus, A. corymbifera, A. niger and C. albicans, respectively at its 2500 ppm dose in the basal medium. Gradual reduction in sporulation in all the test organisms almost in all the sulfadrugs have caused inhibition in sporulation, in comparison to their respective controls. Maximum inhibitory effect of sulfadiazine was recorded in A. niger showing 77.26 percent inhibition in the mycelial growth at a dose of 2500 ppm. Sulfaguanidine at its higher dose i.e., 2500 ppm proved to be most toxic against A. corymbifera causing 56.39 percent inhibition in the mycelial growth, while the same dose could not be found much effective against other test fungi. Sulfamoxole was found to be quite effective against most of the test fungi causing 47.16 to 85.86 percent inhibition in the mycelial growth. A gradual inhibition in the vegetative growth and sporulation or budding in all the test fungi was noted by increasing the concentrations of the test sulfadrugs.

Functional magnetic resonance imaging of the primary motor cortex in humans: response to increased functional demands.

Functional magnetic resonance imaging (fMRI) studies have been performed on 20 right handed volunteers at 1.5 Tesla using echo planar imaging (EPI) protocol. Index finger tapping invoked localized activation in the primary motor area. Consistent and highly reproducible activation in the primary motor area was observed in six different sessions of a volunteer over a period of one month. Increased tapping rate resulted in increase in the blood oxygenation level dependent (BOLD) signal intensity as well as the volume/area of activation (pixels) in the contralateral primary motor area up to tapping rate of 120 taps/min (2 Hz), beyond which it saturates. Activation in supplementary motor area was also observed. The obtained results are correlated to increased functional demands.

Activity of some plant extracts against dermatophytes.

The occurrence of fungal diseases is a serious problem of the present medicine because of the development of drug resistance against the antifungal activities in the pathogen. As compared to antibacterial antibiotics, there are only a few antibiotics which are used against fungal infection besides there is a serious problem of the development of resistance in fungal pathogen against the known antifungals, hence there seems a great demand of some alternative chemotherapeutic agent. The possibility of getting certain active principle in plants are immense, earlier workers have shown the presence of antifungal activity in various plants of varied nature suggest that the search for antifungal of plant origin should continue to explore their potential.

Positron annihilation studies in lysozyme and catalase.

Positron annihilation studies have been carried out in two enzymes, lysozyme and catalase. Temperature dependence of the positron lifetimes in these two enzymes has been investigated. The results explained in terms of the free volume model and fluctuations between different conformational microstates of enzyme structures provide a new insight into the mechanism of bio-activity of these enzymes.

Juxta splenic hydatid cyst.

A forty year old female who presented with intra-abdominal lump in the left hypochondrium was clinically suspected to have a juxta splenic hydatid cyst. Histopathology and cytology of the specimen removed at surgery confirmed the diagnosis.