Growth and production of common bean fertilized with biochar / Crescimento e produção de feijoeiro adubado com biocarvão

ABSTRACT: Production of biochar from organic wastes promises to be an interesting source of plant nutrients, thus reducing pressure on natural resources. To assess the effect of biochar prepared from wastes filtration materials on the growth and production of common bean (Phaseolus vulgaris L.), three simultaneous greenhouse experiments were conducted with three different biochar from organic wastes (rice husk, sawdust, and sorghum silage) using as filtration material for swine biofertilizer. In each experiment the treatments consisted of the addition of five different biochar concentrations (0%, 2.5%, 5%, 7.5%, and 10% v/v), arranged in a completely random design, with four repetitions. Application of biochar increased the root dry mass, shoot dry mass, grain dry mass, number of pods and number of grains. These results indicated that biochar contributed significantly to the growth and production of common bean plants.

RESUMO: A produção de biochar a partir de resíduos orgânicos pode ser uma estratégia agronômica interessante como fonte de nutrientes para as plantas, diminuindo assim, a pressão sobre os recursos naturais. Com o objetivo de avaliar o efeito de biocarvões, produzidos de materiais filtrantes descartados, no crescimento e produção de feijão (Phaseolus vulgaris L.), conduziram-se simultaneamente três experimentos em casa de vegetação. Cada um dos experimentos foi representado pela aplicação de um biochar, os quais foram produzidos a partir de resíduos orgânicos de casca de arroz, serragem e restos de silagem de sorgo, utilizados como material filtrante para o biofertilizante suíno; e os tratamentos avaliados consistiram na adição de cinco níveis de biocarvão, isto é, 0, 2,5%, 5% 7,5% e 10% v/v. Nos três experimentos a aplicação de biochar aumentou a massa seca da raiz, massa seca da parte aérea, massa seca de grãos, número de vagens e número de grãos. Esses resultados indicam que os biochars contribuíram significativamente para o crescimento e produção do feijoeiro.

Isolation and Identification of Cellulytic Fungi from Agrowastes and Sawmill Soils.

Five agricultural wastes and sawmill soil were investigated for fungi capable of producing cellulase. Isolation was carried using serial dilution techniques and isolates were screened for cellulase production on carboxymethyl cellulose-containing agar plates. Copious isolates were further subjected to submerged cultivation for quantitative evaluation of cellulase biosynthesis. Highest fungal load was 6.67±0.33×106 sfu/g (Sawmill soil) and the least was 2.33±0.33×106 sfu/g (yam peels). A total of sixty seven fungi were identified from the samples. The isolates were of fifteen fungal species namely Mucor mucedo, Aspergillus niger, A. repens, A. flavus, A. parasiticus, Articulospora inflata, Gonatobotrys simplex, Gyrothrix circinata, Dendrospora erecta, Penicillium notatum, P. italicum, Varicosporium elodea, Gonatobotryum apicolatum, Mucor racemosus and Rhizopus nigricans. Aspergillus had the highest occurrence (36.11%), while the least occurrence was Varicosporium and Gonatobotryum (2.78%). Highest cellulase activity ratio was exhibited by Aspergillus niger (1.90) and the least by Aspergillus repens (1.04) on plate screening. The highest cellulase producer among selected isolates under submerged growth was Gonatobotrys simplex (1.2143±0.02 U/ml), followed by Aspergillus niger (1.1429±0.01 U/ml) and the least by Aspergillus parasiticus (0.8265±0.01 U/ml). Submerged protein content was highest in Aspergillus niger culture and least in Penicillium notatum. The study has revealed array of cellulytic fungi from agricultural wastes and sawmill soil.

Isolation and Screening of Mannanase Producing Bacteria from Agricultural Wastes.

Aim: The work focused on the isolation and screening of mannanase-producing bacteria associated with selected agricultural wastes. Study Design: The first experiment, mannanase-producing bacteria were screened for mannanase production on Locust Bean Gum (LBG) agar medium and total bacterial count was determined. In the second experiment, the isolated bacteria were further screened for mannanase production in submerged state fermentation. Place and Duration of Study: Microbiology Research Laboratory Federal University of Technology, Akure and Postgraduate Research Laboratory, Obafemi Awolowo University Ile-Ife, Nigeria between September 2011 and March 2012. Methodology: The associated bacterial isolates were isolated on agar medium containing LBG and counted by standard microbiological methods. Quantitatively, mannanase production was conducted in mineral salt medium into which copra meal had been incorporated as the sole carbon source and enzyme activity was determined by dinitrosalicylic acid method. Results: The highest bacteria counts were recorded in compost from wood dust with 5.5×1011 cfu/g, while cassava peels had the least of 1.02×106 cfu/g. In this study, 23 bacterial isolates showed positive results with clear zone around the cultures. Bacterial isolate 1A showed the highest ratio of clear zone to colony, while the lowest was observed in isolate 4B. In liquid broth, all the 23 isolates displayed mannanase activity between 0.28 to13.89 U/ml for static and 0.56 to 13.43 U/ml for shaken condition, with the highest mannanase activity observed with isolate IA for both culture conditions. In the comparative study between static and shaken conditions, it was revealed that shaken cultures exhibited better yield than static cultures. According to the morphological and biochemical studies, the isolate 1A was primarily identified as the Klebsiella edwardsii. Conclusion: In this investigation, bacterial isolates evaluated for mannanase production from agricultural wastes elaborated considerable mannanase activity and this could be applied in feed and prebiotic.

Screening and Identification of Mannanase- Producing Fungi Isolated from Selected Agricultural Wastes.

Aim: The study evaluated potential performance of different fungal isolates from agricultural by-products for mannanase production. Study Design: The first experiment, fungal isolates were screened for mannanase production on agar medium containing Locust Bean Gum (LBG) and total fungal count was conducted. In the second experiment, the fungal isolates were further screened for mannanase production in submerged state fermentation. Place and Duration of Study: Microbiology Research Laboratory Federal University of Technology, Akure and Postgraduate Research Laboratory, Obafemi Awolowo University Ile-Ife, Nigeria between September 2011 and March 2012. Methodology: The fungal isolates associated with some agricultural wastes were isolated on LBG containing agar medium by plate assay techniques and counted by standard microbiological methods. Mannanase production was conducted in submerged state fermentation (shaken & static) into which copra meal had been supplemented as the sole carbon source and enzyme activity was determined by dinitrosalicylic acid method. Results: In this study, 11 fungal isolates showed positive results with clear zone around their cultures. Fungal isolate 5A showed the highest activity ratio of 1.8, while the least was observed in isolate 9A12 with activity ratio of 0.64. The highest fungal counts were recorded in fermented coconut with 7.4×102 sfu/g, while cocoa pod and groundnut shell had no fungal growth. In terms of percentage occurrence of fungal isolates from selected agrowastes, it was revealed that Rhizopus japonicus had the highest occurrence of 66.67%, while the same value of 8.33% was observed for Aspergillus fumigatus, A. glaucus, R. stolonifer and Trichosporonoides oedocephalis. In fermentation broth, all the 11 isolates displayed mannanase activity ranging from 0.370 to 21.667 U/ml for static and 0.278 to 3.982 U/ml for shaken condition, with the highest mannanase activity observed with isolate 5A for both culture conditions. According to the cultural characters and microscopic morphology, the isolate 5A being the highest mannanase producer was identified as the Aspergillus fumigatus. Conclusion: In this study, fungal isolates screened and evaluated for mannanase production from agricultural by-products elaborated considerable mannanase activity and this could be exploited for prebiotic preparation.

Effect of various media and supplements on laccase activity and its application in dyes decolorization

Aims: Marine-derived fungi are a potential for the search of new compounds with relevant features. Among these, the ligninolytic enzymes have potential applications in a large number of fields, including the environmental and industrial sectors. This work aimed to evaluate the laccase activity of the marine-derived fungus Alternaria alternata, under various cultivation conditions and its application in synthetic dyes decolorization. Methodology and results: Wheat bran prepared with 40 mL sea water proportion was the most suitable substrate for laccase production (114.06±2.24 U/mL) by A. alternata, after 14 days of incubation in submerged fermentation. Laccase production in static cultivation was superior to that in agitated cultures. The simple Boyd and Kohlmeyer medium with supplementation of 2 mM CuSO4·5H2O on day 6, at an incubation period of 14 days and incubation temperature of 28±2°C under static conditions, yielded amounts of laccase (36.13±0.34 U/mL) less than that obtained with submerged fermentation of wheat bran as unique substrate. Furthermore, A. alternata has high decolorization capability toward azo dyes in the absence of redox mediators, 75.47% of the reactive black at 0.01% concentration, was removed after 30 days of incubation. Also has good ability to decolorize the triphenylmethane dye crystal violet, at 0.01% concentration, about 69.35% of the dye was removed after 30 days. Conclusion, significance and impact of study: These unusual properties demonstrate that the marine-derived fungus Alternaria alternata has potentials in specific industrial or environmental applications.

Crescimento micelial de Lentinus sajor caju (Fr.) Fr. E Pleurotus spp. em diferentes resíduos agrícolas / Mycelial growth of Lentinus sajor caju (Fr.) Fr. and Pleurotus spp. in different agricutural wastes

O objetivo deste trabalho foi avaliar o desenvolvimento in vitro de três linhagens de cogumelos [Pleurotus ostreatoroseus Singer, Pleurotus pulmonarius (Fr.) Quél. e Lentinus sajor caju (Fr.) Fr.], reativados em meio de cultura BDA e cultivadas em meios de cultura formulados à base de resíduos agrícolas, como a palha de arroz, casca de mamona, casca de amendoim. No meio sólido formulado foi adicionado um disco de cultura no centro da placa, estas foram incubadas a 25oC até a colonização do meio. Avaliou-se, diariamente, o diâmetro da colônia e obteve-se, aos cinco dias de cultivo, a massa miceliana, sendo os resultados obtidos submetidos a análise de variância e teste de Tukey. O meio contendo extrato da casca de amendoim foi o mais adequado para o crescimento da linhagem utilizada de Lentinus sajorcaju, que colonizou 68,30% da placa de Petri. O meio contendo extrato de casca de mamona foi mais favorável ao crescimento de Pleurotus ostreatoreoseus que colonizou 40,01% da placa. A linhagem nativa de Pleurotus pulmonarius cresceu indiferentemente nos meios testados e teve maior crescimento comparada a linhagem de Pleurotus ostreatoroseus. A linhagem de Lentinus sajor-caju no meio contendo extrato da casca de amendoim, apresentou massa micelial seca significativamente maior que todas as demais. O crescimento micelial das linhagens de Lentinus sajor-caju e Pleurotus ostreatoroseus é influenciado pelo meio de cultivo, enquanto o da linhagem nativa utilizada não é influenciado pelos meios testados.

The aim of this study was evaluate the in vitro development of three mushrooms strains [Pleurotus ostreatoroseus Singer, Pleurotus pulmonarius (Fr.) Quél. e Lentinus sajor-caju (Fr.) Fr.], growing media based in agricultural wastes, such rice straw, castor bean seed husks and peanut shells. In the solid medium was added a culture disc in the center of a petri dish and than was incubated at 25oC even the completly colonization of the medium, the data obtained were submitted to variance analysis and Tukey test. Was evaluated, daily, the colony diameter and the mycelial mass obtained after five days of culture. The medium containing peanut husks extract provides the optimal development for the Lentinus sajor-caju strain, when an average of 68.3% of each petri dishes was colonized by mycelia. The medium containig castor bean seed shells were most favorable for Pleurotus ostreatoreoseus development, such colonizing 40,01% of each petri dishes. The wild strain of Pleurotus pulmonarius grew indifferently in the tested media and reaches the higher development when compared with Pleurotus ostreatoroseus strain. Lentinus sajor-caju demonstrate significantly more mycelial dry mass in the peanut shells medium when compared with the others strains. This result suggests that the mycelial growing of Lentinus sajor-caju and Pleurotus ostreatoroseus are influencied by the media. For the wild strain the mycelial growing its not significantly influencied by the tested media.

Hydrolysis of various thai agricultural biomasses using the crude enzyme from Aspergillus aculeatus iizuka FR60 isolated from soil

In this study, forty-two fungi from soil were isolated and tested for their carboxymethyl cellulase (CMCase) and xylanase activities. From all isolates, the fungal isolate FR60, which was identified as Aspergillus aculeatus Iizuka, showed high activities in both CMCase and xylanase with 517 mU/mg protein and 550 mU/mg protein, respectively. The crude enzyme from A. aculeatus Iizuka FR60 could hydrolyze several agricultural residues such as corncob, and sweet sorghum leaf and stalk at comparable rates with respect to the tested commercial enzymes and with a maximum rate in rice hull hydrolysis (29 μg sugar g-1 dry weight substrate mg-1 enzyme hr-1). The highest amount of glucose was obtained from corncob by using the crude enzyme from A. aculeatus Iizuka FR60 (10.1 g/100 g dry substrate). From overall enzymatic treatment results, the lowest sugar yield was from rice hulls treatment (1.6 g/100 g dry weight) and the highest amount of reducing sugar was obtained from rice straw treatment (15.3 g/100 g dry weight). Among tested agricultural wastes, rice hull could not be effectively hydrolyzed by enzymes, whereas sugarcane leaf and stalk, and peanut shell could be effectively hydrolyzed (30-31% total sugar comparing with total sugar yield from acid treatment).

Production of Xylanolytic Enzyme Complex from Aspergillus flavus using Agricultural Wastes

Five types of agricultural wastes were used for the production of xylanolytic enzyme by Aspergillus flavus K-03. All wastes materials supported high levels of xylanase and beta-xylosidase production. A high level of proteolytic activity was observed in barley and rice bran cultures, while only a weak proteolytic activity was detected in corn cob, barley and rice straw cultures. Maximum production of xylanase was achieved in basal liquid medium containing rice barn as carbon source for 5 days of culture at pH 6.5 and 25degrees C. The xylanolytic enzyme of A. flavus K-03 showed low thermostability. The times required for 50% reduction of the initial enzyme activity were 90 min at 40degrees C, 13 min at 50degrees C, and 3 min at 60degrees C. Xylanolytic activity showed the highest level at pH 5.5~10.5 and more than 70% of the original activity was retained at pH 6.5 and 7.0. The higher stability of xylanolytic enzymes in the broad range of alkaline pH is useful for utilization of the enzymes in industrial process requiring in alkaline conditions. Moreover, the highest production of xylanolytic enzyme was obtained when 0.5% of rice bran was supplied in basal liquid medium. SDS-PAGE analysis revealed a single xylanase band of approximately 28.5 kDa from the culture filtrates.