Suitability of some local agro-industrial wastes as carrier materials for cyanobacterial inoculant

Survival and nitrogenase efficiency ofNostoc commune andN. austinii were evaluated monthly in four carrier materials (sugarcane bagasse, wheat straw, wheat bran and peat) at 10, 30 and 40 °C. Survival, as well as nitrogenase activity, of both species was much better in peat, followed by wheat bran, sugarcane bagasse than in wheat straw at 10 and 30 °C up to three months, the activity ofN. commune being better thanN. austinii. None of the materials tested was found to be superior to peat as carrier ofNostoc species but the results indicated that wheat bran and sugarcane bagasse can be used as inoculant carriers with relative success. Storage of inoculants in these carriers is feasible at 30 °C up to three months.     

Development of formulations of biological agents for management of root rot of lettuce and cucumber

The effect of various carrier formulations of Bacillus subtilis and Pseudomonas putida were tested on germination, growth, and yield of lettuce and cucumber crops in the presence of Pythium aphanidermatum and Fusarium oxysporum f.sp. cucurbitacearum, respectively. Survival of B. subtilis and P. putida in various carriers under refrigeration (about 0 degree C) and at room temperature (about 22 degrees C) was also studied. In all carrier formulations, B. subtilis strain BACT-0 survived up to 45 days. After 45 days of storage at room temperature (about 22 degrees C), populations B. subtilis strain BACT-0 were significantly higher in vermiculite, kaolin, and bacterial broth carriers compared with other carriers. Populations of P. putida were significantly higher in vermiculite, peat moss, wheat bran, and bacterial broth than in other carriers when stored either under refrigeration (about 0 degree C) or at room temperature (about 22 degrees C) for 15 or 45 days. Germination of lettuce seed was not affected in vermiculite, talc, kaolin, and peat moss carriers, but germination was significantly reduced in alginate and bacterial broth carriers of B. subtilis compared to the non-treated control. Germination of cucumber seed was not affected by any of the carriers. Significantly higher fresh lettuce and root weights were observed in vermiculite and kaolin carriers of B. subtilis compared with P. aphanidermatum-inoculated control plants. Lettuce treated with vermiculite, and kaolin carriers of B. subtilis, or non-inoculated control lettuce plants had significantly lower root rot ratings than talc, peat moss, bacterial broth, and P. aphanidermatum-inoculated control plants. Growth and yield of cucumber plants were significantly higher in vermiculite-based carrier of P. putida than the other carriers and Fusarium oxysporum f.sp. cucurbitacearum-inoculated plants.     

Mixture design as first step for improved glutaminase production in solid-state fermentation by isolated Bacillus

Aim: Investigation of mixture‐design impact on glutaminase production by isolated Bacillus sp. Methods and Results: An augmented simplex centroid design was used to optimize a three (wheat bran, Bengal gram husk and palm seed fibre) component mixture for glutaminase production. Selected substrate materials showed impact on glutaminase production values at individual level by Bengal gram husk [2789 U gds^?1 (gram dry substrate] and in two‐level combination with wheat bran and Bengal gram husk (maximum of 3300 U gds^?1). Conclusion: Bengal gram husk is the most suitable substrate medium for glutaminase production by Bacillus sp. Maximum glutaminase production is achieved using solid‐substrate mixture at two‐level combinations in the ratio of 66 : 34 for Bengal gram husk and wheat bran, respectively. Significance and Impact of the Study: The present study has significance in large‐scale production of glutaminase at commercial level with the use of multi‐substrate rather than single‐substrate/support material.     

Use of plant residues for improving soil fertility, pod nutrients, root growth and pod weight of okra (Abelmoschus esculentum L)

The effect of wood ash, sawdust, ground cocoa husk, spent grain and rice bran upon root development, ash content, pod yield and nutrient status and soil fertility for okra (Abelmoschus esculentum L NHAe 47 variety) was studied. The five organic fertilizer treatments were compared to chemical fertilizer (400kg/ha/crop NPK 15-15-15) and unfertilized controls in four field experiments replicated four times in a randomized complete block design. The results showed that the application of 6tha(-1) of plant residues increased (P<0.05) the soil N, P, K, Ca, Mg, pH, and SOM; pod N, P, K, Ca, Mg and ash; root length; and pod yield of okra in all four experiments relative to the control treatment. For instance, spent grain treatment increased the okra pod yield by 99%, 33%, 50%, 49%, 65% and 67% compared to control, NPK, wood ash, cocoa husk, rice bran and sawdust treatments respectively. In the stepwise regression, out of the total R(2) value of 0.83 for the soil nutrients to the pod yield of okra; soil N accounted for 50% of the soil fertility improvement and yield of okra. Spent grain, wood ash and cocoa husk were the most effective in improving okra pod weight, pod nutrients, ash content, root length and soil fertility whereas the rice bran and sawdust were the least effective. This was because the spent grain, wood ash and cocoa husk had lower C/N ratio and higher nutrient composition than rice bran and sawdust, thus, the former enhanced an increase in pod nutrients, composition for better human dietary intake, increased the root length, pod weight of okra and improved soil fertility and plant nutrition crop. The significance of the increases in okra mineral nutrition concentration by plant residues is that consumers will consume more of these minerals in their meals and monetarily spend less for purchasing vitamins and mineral supplement drugs to meet health requirements. In addition, the increase in plant nutrition and soil fertility would help to reduce the high cost of buying synthetic inorganic fertilizers and maintain the long term productivity of soils for sustainable cultivation of okra.     

Production and optimization of process parameters for alkaline protease production by a newly isolated Bacillus sp. under solid state fermentation

Production of alkaline protease employing the laboratory isolate, Bacillus sp. under solid state fermentation (SSF) was optimized. The effect of wheat bran and lentil husk was examined. Wheat bran showed highest enzyme production. The appropriate incubation time, inoculum size, moisture level and buffer solution level were determined. Maximum yields of 429.041 and 168.640 U g⁻¹ were achieved by employing wheat bran and lentil husk as substrates in 0.1 M carbonate/bicarbonate buffer at pH 10 with 30 and 40% initial moisture level at 24 h. Inoculum size and buffer solution level were found to be 20 and 25% and 0.5:1 for wheat bran and lentil husk, respectively.     

Effects of carrier, sterilisation method, and incubation on survival of Bradyrhizobium japonicum in soybean (Glycine max L.) inoculants

The production and quality of rhizobial inoculants in many developing countries is limited by the availability of suitable carriers or technological limitations. Experiments were conducted to evaluate the potential of various inexpensive and widely available carrier materials. The carriers, evaluated, were: perlite with pH adjusted with calcium carbonate or charcoal, 1:4 mixtures of perlite and malt residue, sugarcane bagasse, coal, and rice husk. We also contrasted sterilisation procedures (autoclaving or gamma irradiation) and incubation after injection (with or without initial two weeks incubation at 28 °C) for these various carriers. Survival of Bradyrhizobium japonicum strain CB1809 was monitored over a period of 6 months upon storage at 4 °C. Most carriers evaluated, were able to maintain rhizobial populations of more than 1 × 10⁹ rhizobia per gram of inoculant over that time period, with mixtures of perlite with either sugarcane bagasse or malt residue supporting the largest rhizobial populations and a mixture of perlite and rice husk the lowest. All carriers supported rhizobial growth over the 6 months period. Initially, rhizobial populations were greater with gamma irradiation than autoclaving, however after 6 months, this response was significant only with the perlite and sugarcane bagasse mixture. The incubation of the inoculant after injection also ultimately did not benefit rhizobial levels for any of the carriers, tested. Using simple sterilisation procedures and without incubating after injection, perlite based carriers can produce high quality inexpensive inoculants, maintaining bacterial populations of more than 1 × 10⁹/g rhizobia for at least 6 months.     

Fermentative production of dl-lactic acid from amylase-treated rice and wheat brans hydrolyzate by a novel lactic acid bacterium, Lactobacillus sp.

Rice and wheat brans, without additional nutrients and hydrolyzed by alpha-amylase and amyloglucosidase, were fermented to DL-lactic acid using a newly isolated strain of Lactobacillus sp. RKY2. In batch fermentations at 36 degrees C and pH 6, the amount of lactic acid in fermentation broth reached 129 g l(-1) by supplementation of rice bran with whole rice flour. The maximum productivity was 3.1 g lactic acid l(-1) h(-1) in rice bran medium supplemented with whole rice flour or whole wheat flour.     

Production of extracellular alkaline alpha-amylase by solid state fermentation with a newly isolated Bacillus sp

Production of alkaline alpha-amylase employing our laboratory isolate, Bacillus sp., under solid state fermentation, was optimized. The effect of wheat bran and lentil husk was examined. Lentil husk exhibited the highest enzyme production. The appropriate incubation time, inoculum size, moisture level, and buffer solution level were determined. Maximum yields of 216,000 and 172,800 U/g were achieved by employing lentil husk and wheat bran as substrates in 0.1 M carbonate/bicarbonate buffer at pH 10.0 with 30% initial moisture level at 24 h. Inoculum size and buffer solution level were found to be 20% and 1:0.5 for two solid substrates.     

Evaluation of shelf life and rock phosphate solubilization of Burkholderia sp. in nutrient-amended clay, rice bran and rock phosphate-based granular formulation

Five phosphate-solubilizing bacteria (PSB) used in this study were isolated based on their ability to solubilize tricalcium phosphate (TCP) in Pikovskaya’s medium. Among the tested bacterial strains Burkholderia sp. strain CBPB-HIM showed the highest solubilization (363 μg of soluble P ml⁻¹) activity at 48 h of incubation. Further, this strain has been selected to assess its shelf life in nutrient-amended and -unamended clay, rice bran and rock phosphate (RP) pellet-based granular formulation. The results showed that the maximum viability of bacterium was observed in clay and rice bran (1:1) + 10% RP pellets than clay-RP pellets, irrespective of tested storage temperatures. Further, clay and rice bran (1:1) + 10% RP pellets amended with 1% glucose supported the higher number of cells compared to glycerol-amended and nutrient-unamended pellets. In this carrier solubilization of Morocco rock phosphate (MRP) by Burkholderia sp. strain CBPB-HIM was also investigated. The maximum of water and bicarbonate extractable P (206 and 245 μg P g⁻¹ of pellet respectively) was recorded in clay and rice bran (1:1) + 10% RP pellets amended with 1% glucose and glycerol respectively on day 5 of incubation. Therefore, this study proved the possibility of developing granular inoculant technology combining clay, rice bran and RP as substrates with phosphate-solubilizing Burkholderia.     

Production of Extracellular Alkaline α‐Amylase by Solid State Fermentation with a Newly Isolated Bacillus sp.

Abstract

Production of alkaline α‐amylase employing our laboratory isolate, Bacillus sp., under solid state fermentation, was optimized. The effect of wheat bran and lentil husk was examined. Lentil husk exhibited the highest enzyme production. The appropriate incubation time, inoculum size, moisture level, and buffer solution level were determined. Maximum yields of 216,000 and 172,800 U/g were achieved by employing lentil husk and wheat bran as substrates in 0.1 M carbonate/bicarbonate buffer at pH 10.0 with 30% initial moisture level at 24 h. Inoculum size and buffer solution level were found to be 20% and 1:0.5 for two solid substrates.     

丛枝菌根真菌状巨孢囊霉孢子伴生细菌的绿色荧光蛋白标记及定殖分析

摘要：【目的】分析丛枝菌根（Arbuscualr Mycorrhizal, AM）真菌珠状巨孢囊霉(Gigaspora margarita) MAFF 520054孢子伴生细菌的定殖情况,明确其生态位点,以及为进一步分析其种群生态或功能提供信息。【方法】以载体pNF8（gfp-mut1）对6株珠状巨孢囊霉MAFF 520054 孢子伴生细菌进行绿色荧光蛋白（GFP）标记,并通过荧光显微镜和平板计数的方法研究标记菌株对真菌宿主的定殖位点和不同条件下的定殖数量动态。【结果】对粘状芽孢杆菌（Peanibacillus spp.）M060106-1和M061122-6、芽孢杆菌（Bacillus sp.）M061122-10和短小芽孢杆菌（Brevibacillus sp.）M061122-12成功进行了GFP标记,其均具有较好的质粒稳定性,且与出发株的基本性状一致,适合短期内进行环境定殖研究。所有菌株均能定殖珠状巨孢囊霉MAFF 520054孢子壁,而M061122-6和M061122-12还能够定殖其菌丝;不同pH值条件下,各菌株定殖珠状巨孢囊霉MAFF 520054孢子的数量动态均为先上升后下降,pH值对各菌株的定殖数量有不同的影响;各GFP菌株对低活力的珠状巨孢囊霉孢子定殖数量高于高活力的孢子,且对高活力孢子的定殖数量动态不同。【结论】分离的珠状巨孢囊霉孢子伴生细菌能够重新定殖其孢子,菌株的定殖能力受其特性及外界因子的影响,为进一步分析AM真菌伴生细菌的种群生态及功能提供了信息。     

Use of response surface methodology for optimizing process parameters for high inulinase production by the marine yeast <Emphasis Type="Italic">Cryptococcus aureus</Emphasis> G7a in solid-state fermentation and hydrolysis of inulin

The optimization of process parameters for high inulinase production by the marine yeast strain Cryptococcus aureus G7a in solid-state fermentation (SSF) was carried out using central composite design (CCD), one of the response surface methodologies (RSMs). We found that moisture, inoculation size, the amount ratio of wheat bran to rice husk, temperature and pH had great influence on inulinase production by strain G7a. Therefore, the CCD was used to evaluate the influence of the five factors on the inulinase production by strain G7a. Then, five levels of the five factors above were further optimized using the CCD. Finally, the optimal parameters obtained with the RSM were the initial moisture 61.5%, inoculum 2.75%, the amount ratio of wheat bran to rice husk 0.42, temperature 29 °C, pH 5.5. Under the optimized conditions, 420.9 U g⁻¹ of dry substrate of inulinase activity was reached in the solid-state fermentation culture of strain G7a within 120 h whereas the predicted maximum inulinase activity of 436.2 U g⁻¹ of inulinase activity of 436.2 U g⁻¹ of dry weight was derived from the RSM regression. This is the highest inulinase activity produced by the yeast strain reported so far. A large amount of monosaccharides and oligosaccharides were detected after inulin hydrolysis by the crude inulinase.     

Effects of carrier,sterilisation method,and incubation on survival of Bradyrhizobium japonicum in soybean (Glycine max L.) inoculants

The production and quality of rhizobial inoculants in many developing countries is limited by the availability of suitable carriers or technological limitations. Experiments were conducted to evaluate the potential of various inexpensive and widely available carrier materials. The carriers, evaluated, were: perlite with pH adjusted with calcium carbonate or charcoal, 1:4 mixtures of perlite and malt residue, sugarcane bagasse, coal, and rice husk. We also contrasted sterilisation procedures (autoclaving or gamma irradiation) and incubation after injection (with or without initial two weeks incubation at 28 °C) for these various carriers. Survival of Bradyrhizobium japonicum strain CB1809 was monitored over a period of 6 months upon storage at 4 °C. Most carriers evaluated, were able to maintain rhizobial populations of more than 1 × 10⁹ rhizobia per gram of inoculant over that time period, with mixtures of perlite with either sugarcane bagasse or malt residue supporting the largest rhizobial populations and a mixture of perlite and rice husk the lowest. All carriers supported rhizobial growth over the 6 months period. Initially, rhizobial populations were greater with gamma irradiation than autoclaving, however after 6 months, this response was significant only with the perlite and sugarcane bagasse mixture. The incubation of the inoculant after injection also ultimately did not benefit rhizobial levels for any of the carriers, tested. Using simple sterilisation procedures and without incubating after injection, perlite based carriers can produce high quality inexpensive inoculants, maintaining bacterial populations of more than 1 × 10⁹/g rhizobia for at least 6 months.     

Production of cellulase-free endoxylanase from novel alkalophilic thermotolerent Bacillus pumilus by solid-state fermentation and its application in wastepaper recycling

The present study aimed at optimization of culture condition for the enhanced production of extra cellular thermostable cellulase-free xylanase from Bacillus pumilus by solid-state fermentation. Batch studies were carried out to evaluate various agro-industrial residues such as rice bran, rice husk, rice straw, sawdust, coconut pith, sugarcane bagasse and wheat bran for enzyme production by the bacterial culture. The endoxylanase production was highest on wheat bran media (5582 U/gds), which was enhanced 3.8-fold (21,431 U/gds) by optimization of cultivation conditions. The enzymatic extracts was used in mixed wastepaper recycling, which resulted in a considerable improvement of the paper strength with high drainage and easy drying up. The results of enzyme application with recycled paper clearly indicated that the effective use of enzymes in fiber separation could reduce the cost of carton paper production.     

Parametric optimization of feruloyl esterase production from Aspergillus terreus strain GA2 isolated from tropical agro-ecosystems cultivating sweet sorghum

A fungal strain, Aspergillus terreus strain GA2, isolated from an agricultural field cultivating sweet sorghum, produced feruloyl esterase using maize bran. In order to obtain maximum yields of feruloyl esterase, the solid state fermentation (SSF) conditions for enzyme production were standardized. Effective feruloyl esterase production was observed with maize bran as substrate followed by wheat bran, coconut husk, and rice husk among the tested agro-waste crop residues. Optimum particle size of 0.71- 0.3 mm and moisture content of 80% favored enzyme production. Moreover, optimum feruloyl esterase production was observed at pH 6.0 and a temperature of 30 degrees C. Supplementation of potato starch (0.6%) as the carbon source and casein (1%) as the nitrogen source favored enzyme production. Furthermore, the culture produced the enzyme after 7 days of incubation when the C:N ratio was 5. Optimization of the SSF conditions revealed that maximum enzyme activity (1,162 U/gds) was observed after 7 days in a production medium of 80% moisture content and pH 6.0 containing 16 g maize bran [25% (w/v)] of particle size of 0.71-0.3 mm, 0.6% potato starch, 3.0% casein, and 64 ml of formulated basal salt solution. Overall, the enzyme production was enhanced by 3.2-fold as compared with un-optimized conditions.     

Production of alpha amylase by Bacillus licheniformis using an economical medium

The present study is concerned with the selection of new medium for the production of alpha amylase by Bacillus licheniformis. Different agricultural by-products such as wheat bran, sunflower meal, cotton seed meal, soybean meal, rice husk or rice bran were tested for the production of alpha amylase. Among different agricultural by-products evaluated, wheat bran was found to be the best basal and standardized medium for optimal production of alpha amylase. The production was increased 2-folds when soluble starch was replaced with pearl millet starch at 1% level and nutrient broth concentrations was reduced from 1% level to 0.5%. The newly selected fermentation medium containing (% w/v) wheat bran 1.25, nutrient broth 0.5, pearl millet starch 1.0, lactose 0.5, NaCl 0.5, CaCl2 0.2 in 100 ml of phosphate buffer. The kinetic values of Y(p/x), Y(p/s), and Q(p) indicated that the production of enzyme was greater in newly selected medium than the conventional more expensive medium.     

High level of sporulation ofMetarhizium anisopliae in a medium containing by-products

Summary Solid-state fermentation of rice bran or rice-bran-husk mixtures byMetarhizium anisopliae proved to be highly successful in spore yield. Optimum sporulation response on bran medium occurred when the initial water activity values ranged from 0.982 to 0.999. When bran was supplemented with 50% rice husk, the spore yield almost doubled, but a narrower initial water activity range (0.997–0.999) was optimum. Under these conditions, spore yields were 5–15 times higher (depending on the strain) than those currently obtained on the basis of rice grain fermentations.     

Hydrolysis of wheat bran,rice bran and jute powder by immobilized enzymes from Macrophomina phaseolina

The stability of cellulolytic and hemicellulolytic enzymes from Macrophomina phaseolina improved on immobilization and was 1.5 to 2-fold more active against pre-treated wheat bran, rice bran or jute powder. The hydrolysis efficiency of the catalyst increased with a decrease in its particle size. About 80% (w/v) of the sugar obtained from wheat bran was assimilated by Saccharomyces sp., whereas the corresponding values for rice bran and jute powder were about 70 and 50% (w/v), respectively.     

Response surface methodology for the optimization of <Emphasis Type="Italic">α</Emphasis>-amylase production by <Emphasis Type="Italic">Streptomyces</Emphasis> sp. ML12 using agricultural byproducts

Amylases constitute one of the most important groups of enzymes for commercial use. In the present study, production of α-amylase was optimized using a newly isolated actinobacterial strain from the coral reef environment of the Gulf of Mannar Biosphere Reserve, India. It was identified as Streptomyces sp. ML12 based on chemotaxonomy, cultural and morphological characteristics, carbon source utilization and 16S rRNA gene sequencing. Fermentation variables were selected in accordance with the Plackett-Burman design and were optimized by response surface methodology. Five significant variables (rice bran and wheat bran — both agricultural byproducts, sodium chloride, magnesium sulphate and incubation period) were selected for the optimization via central composite design. The optimal features were rice bran (5.5 g/100 mL), wheat bran (5.3 g/100 mL), sodium chloride (2.8 g/100 mL), magnesium sulphate (1.4 g/100 mL) and 8 days of incubation period. Optimization of the medium with the above tested features increased the amylase yield by 4.4-fold.     

Degradation of toxaphene by Bjerkandera sp. strain BOL13 using waste biomass as a cosubstrate

The white-rot fungus Bjerkandera sp. strain BOL13 was capable of degrading toxaphene when supplied with wood chips, wheat husk or cane molasses as cosubstrates in batch culture experiments. Approximately 85% of toxaphene was removed when wheat husk was the main substrate. The production of lignin peroxidase was only stimulated when wheat husk was present in the liquid medium. Although xylanase was always detected, wheat husk supported the highest xylanase production. A negligible amount of β-glucosidase and cellulase were found in the batch culture medium. To the best of our knowledge, this is the first reported case of toxaphene degradation by white-rot fungi.