Biocontrol and other beneficial activities of Bacillus subtilis isolated from cowdung microflora.

Bacillus subtilis strains isolated from cowdung (CD) had several beneficial attributes, which included biocontrol, plant growth promotion, sulphur (S) oxidation, phosphorus (P) solubilization and production of industrially important enzymes (amylase and cellulase). The B. subtilis strains from CD inhibited the in vitro growth of fungi, Fusarium oxysporum (25-34%) and Botryodiplodia theobromae (100%), isolated from the postharvest rots of yam (Dioscorea rotundata) tubers. Other than biocontrol, B. subtilis strains were able to promote root elongation in seedlings of Cicer arietinum up to 70-74% as compared to untreated seeds (control). B. subtilis strains had also the ability to oxidize elemental S to sulphate (2-15microgml(-1)) and showed distinct P-solubilization activity in vitro. In addition, the cultures showed cellulase activity in carboxy methyl cellulose medium (1.5-1.8mg of reducing sugar24h(-1)ml(-1)) and amylase activity in vitro.

Biocontrol efficacy of Bacillus subtilis strains isolated from cow dung against postharvest yam (Dioscorea rotundata L.) pathogens.

The biocontrol potential of Bacillus subtilis isolated from cow dung microflora was investigated in vitro and in vivo against two postharvest yam pathogenic fungi, Fusarium oxysporum and Botryodiplodia theobromae. B. subtilis strains inhibited the growth of F. oxysporum and B. theobromae in vitro in liquid medium in the range of 49.3-56.6% and in solid medium in the range of 31.0-36.0%, in comparison to the corresponding growth of fungi without bacterial inoculation. The interaction between B. subtilis CM1 and F. oxysporum was also studied by scanning electron microscopy. Chitinase production was demonstrated in vitro when B. subtilis was grown in the presence of colloidal chitin as the sole carbon source in a liquid medium. In vivo study showed that B. subtilis strains inhibited the growth of fungi (F. oxysporum and B. thobromae) up to 83% in wound cavities of yam tubers.

Alpha-amylase production by Bacillus subtilis CM3 in solid state fermentation using cassava fibrous residue.

In extraction of starch from cassava (Manihot esculenta Crantz), one of the major solid waste released is fibrous residues which constitute 15-20% by weight of the cassava chips/tuber processed. Production of alpha -amylase under solid state fermentation by Bacillus subtilis CM3 has been investigated using cassava fibrous residue. Response surface methodology (RSM) was used to evaluate the effect of the main variables, i.e. incubation period, initial medium pH, moisture holding capacity and temperature on enzyme production. A full factorial Central Composite Design (CCD) was applied to study these main factors that affected alpha -amylase production. The experimental results showed that the optimum incubation period, initial medium pH, moisture holding capacity and temperature were 6 days, 8.0, 70% and 50 degrees C, respectively.

Ethanol fermentation of mahula (Madhuca latifolia L.) flowers using free and immobilized yeast Saccharomyces cerevisiae.

There is a growing interest to find alternate bioresources for production of ethanol, apart from cane/sugar beet molasses and starchy crops like sweet sorghum, cassava and sweet potato. Mahula (Madhuca latifolia L.) is a forest tree abundantly available in the Indian subcontinent and its flowers are very rich in fermentable sugars (28.1-36.3 g 100 g(-1)). Batch fermentation of fresh and 12-month-stored flowers with free (whole cells) and immobilized cells of Saccharomyces cerevisiae (strain CTCRI) was carried out in 2-l Erlenmeyer flasks. The ethanol yields were 193 and 148 g kg(-1) (using free cells) and 205 and 152 g kg(-1) (using immobilized cells) from fresh and 12-month-stored mahula flowers, respectively.

Post harvest spoilage of sweetpotato in tropics and control measures.

Sweetpotato storage roots are subjected to several forms of post harvest spoilage in the tropical climate during transportation from farmers' field to market and in storage. These are due to mechanical injury, weight loss, sprouting, and pests and diseases. Sweetpotato weevil is the single most important storage pest in tropical regions for which no control measures or resistant variety are yet available. Several microorganisms (mostly fungi) have been found to induce spoilage in stored sweetpotatoes. The most important among them are Botryodiplodia theobromae, Ceratocystis fimbriata, Fusarium spp., and Rhizopus oryzae. The other less frequently occurring spoilage microorganisms include Cochliobolus lunatus (Curvularia lunata), Macrophomina phaseolina, Sclerotium rolfsii, Rhizoctonia solani, Plenodomus destruens. Microbial spoilage of sweetpotato is found associated with decrease in starch, total sugar, organic acid (ascorbic acid and oxalic acid) contents with concomitant increase in polyphenols, ethylene, and in some instances phytoalexins. Several methods are used to control microbial spoilage. Curing to promote wound healing is found as the most suitable method to control microbial spoilage. Curing naturally occurs in tropical climates where mean day temperature during sweetpotato harvesting season (February-April) invariably remains at 32-35 degrees C and relative humidity at 80-95%. Sweetpotato varieties varied in their root dry matter content, and low root dry matter content attributed for their high curing efficiency. Curing efficiency of varieties also differed in response to curing periods. Fungicide treatment, bio-control, gamma irradiation, hydro warming, and storage in sand and saw dust were found to have intermediate impacts in controlling spoilage and enhancing shelf life of sweetpotato roots. Breeding program has to be chalked out to develop new varieties suitable to curing under tropical conditions in addition to developing varieties having multi-spectrum resistance to major post harvest rot pathogens and sweetpotato weevils.

Extracellular amylase(s) production by fungi Botryodiplodia theobromae and Rhizopus oryzae grown on cassava starch residue.

The fungi Botryodiplodia theobromae and Rhizopus oryzae produce extracellular amylase when grown on a liquid medium containing 2% (WN) soluble starch or cassava starch residue(CSR) (as starch equivalent), a waste generated after extraction of starch from cassava, as the sole carbon source. Using CSR as the sole carbon source, the highest amylase activity of 3.25 and 3.8 units (mg, glucose released x ml(-1) x h(-1)) were obtained in shake flask cultures during the late stationary phase of growth of B. theobromae and R. oryzae, respectively. These values were slightly lower than the values obtained using soluble starch as the carbon source. Maximum enzyme synthesis in CSR incorporated medium occurred at the growth temperature of 30 degrees C and pH 6.0. Presence of inorganic NH4+ salts like ammonium acetate and ammonium nitrate in culture medium yielded more amylase than the other nitrogen sources. Amylase(s) production in the controlled environment of a Table-Top glass Jar Fermenter (2-L capacity) was 4.8 and 5.1 units for B. theobromae and R. oryzae, respectively using CSR as the carbon substrate. It is concluded that CSR, a cheap agricultural waste obtained after starch extraction from cassava could replace soluble starch as carbon substrate for commercial production of fungal amylase(s).

Chronic muscle wasting in alcoholics--a histochemical and biochemical study.

A comparative histochemical and biochemical study of the anterior tibial muscle of 10 alcoholics suggests that neuropathy could be the cause of chronic muscle weakness and wasting. Myopathic changes did not predominate in the findings. It is concluded that the proximal muscle atrophy could also be attributed to neurogenic damage. Histochemical reactions in muscle specimens show a selective type 2 atrophy and a slight increase in the mean diameter of type 1 fibres. Biochemical investigations reveal that the activities of a number of enzymes representative of energy supplying pathways--the glycogenolysis and glycolysis--as well as acid phosphatase activity in the muscle is lowered. Oxidative enzymes are of similar activity in the alcoholics and the control group. The glycolytic enzyme activity is particularly important, being the most sensitive indicators of the onset, intensity, and course of neurogenic damage.

Locked in state. A clinicopathological study.

Two patients developed the locked-in state characterised by quadriplegia and mutism with an alert sensorium. Initially they had mild dysarthria and uncrossed hemisensory or hemimotor deficits involving the face and ipsilateral extremities. Both patients died. Rostral brainstem infarctions were found at autopsy in them. Acute onset of uncrossed hemisensory and hemimotor deficits with dysarthria may be caused by infarction of the pons which may predispose to locked-in state.

Primary intraorbital meningioma and schwannoma--a rare association.

Primary intraorbital meningioma and Schwannoma are rare tumours. For them to occur concurrently, or one following soon after another should be considered a curiosity. We present a 40 year old male who reported with proptosis of the right eye and a meningioma was removed surgically. Within 3 months symptoms recurred and a schwannoma was removed at surgery from the same site. Interesting features of the lesion are presented and discussed.

Posterior fossa epidermoid cysts.

Epidermoid cysts in the central nervous system are rare tumours of controversial origin occurring mostly in the last adult age. We present here a series of four cases seen during the last five years. Their common clinical and histological features along with available literature have been discussed.

Carcinoid tumours of the anorectum.

Carcinoid tumours of the anorectum are very rare and comprise only 0.1 per cent of all rectal tumours. Their behaviour and treatment are still debatable. We identified 8 cases during a ten year period from records of two service hospitals; 6 were benign and 2 were malignant. Salient clinical and pathological features have been discussed. All benign tumours were cured by local treatment. Both patients with malignant tumours died despite radical surgical treatment.

Primary hydatid cyst of the brain in an adult: report of a case.

Primary hydatid cyst of the brain in adults is rare and may pose multiple diagnostic problems. A 27-year-old man who presented with mild headache was diagnosed as having an isolated hydatid cyst of the brain. Computed tomographic findings, precautions at operation, and the risk of dissemination are discussed, and available literature is reviewed.