Newton Pereira Stamford

Production and characterization of a thermostable α-amylase from Nocardiopsis sp. endophyte of yam bean

Thermostable amylolytic enzymes have been currently investigated to improve industrial processes of starch degradation. Studies on production of alpha-amylase by Nocardiopsis sp., an endophytic actinomycete isolated from yam bean (Pachyrhizus erosus L. Urban), showed that higher enzyme levels were obtained at the end of the logarithmic growth phase after incubation for 72 h at pH 8.6. Maximum activity of alpha-amylase was obtained at pH 5.0 and 70 degrees C. The isolated enzyme exhibited thermostable properties as indicated by retention of 100% of residual activity at 70 degrees C, and 50% of residual activity at 90 degrees C for 10 min. Extracellular enzyme from Nocardiopsis sp. was purified by fractional precipitation with ammonium sulphate. After 60% saturation produced 1130 U mg-1 protein and yield was 28% with purification 2.7-fold. The enzyme produced by Nocardiopsis sp. has potential for industrial applications.

Production and characterization of a thermostable glucoamylase from Streptosporangium sp. endophyte of maize leaves

Thermostable amylolytic enzymes are currently investigated to improve industrial processes of starch degradation. Streptosporangium sp. an endophytic actinomycete isolated from leaves of maize (Zea mays L.) showed glucoamylase production, using starch-Czapek medium, and the highest rate was obtained in the initial growth phase, after incubation for 24 h at pH 8.0. Maximum glucoamylase activity (158 U mg(-1) protein) was obtained at pH 4.5 and 70 degrees C. The isolated enzyme exhibited thermostable properties as indicated by retention of 100% of residual activity at 70 degrees C for 30 min with total inhibition at 100 degrees C. Extracellular enzyme from Streptosporangium sp. was purified by fractionated precipitation with ammonium sulphate. After 60% saturation produced 421 U mg(-1) protein, and yield was 74% with purification 2.7 fold. The enzyme produced by Streptosporangium sp. has potential for industrial applications.

Growth of Cunninghamella elegans UCP 542 and production of chitin and chitosan using yam bean medium

Microbiological processes were used for chitin and chitosan productions by Cunninghamella elegans (UCP 542) grown in a new economic culture medium. The assay was carried out to evaluate the growth of C. elegans using yam bean ( Pachyrhizus erosus L. Urban) medium, in different times of growth (24, 48, 72 and 96 hrs), incubated at 28oC in an orbital shaker at 150 rpm. The lyophilized biomass was determined by gravimetry. The polysaccharides were extracted by alkali-acid treatment, and characterized by infrared spectroscopy, titration and viscosity. C. elegans grown in the yam bean medium and produced higher yields of biomass (24.3 g/ mL) in 96 hrs. The high level was chitosan (66 mg/g), and chitin (440 mg/g) were produced at 48 and 72 hrs of growth, respectively. The polysaccharides showed degree of deacetilation and viscosimetric molecular weight as: 6.2% and 3.25 x10 4 g/mol for chitin, and 85% and 2.72 x 10 4 g/mol for chitosan, respectively. The results obtained suggest high biotechnological potential of yam bean as an economic source to produce chitin and chitosan by C. elegans . In addition, the new medium using yam bean for production of the chitin and chitosan may be used for many purposes to reduce the cost price of fermentation processes.

Caracterização de rizóbios isolados de Jacatupé cultivado emsolo salino do Estado de Pernambuco, Brasil

Investigation on microbiological biodiversity in the saline soils involves searching for tolerant genotypes to this type of emvironmental stress. Genotypic data associated to morphologic, physiological and biochemical characteristics of bacteria provide important information regarding its identification and clusters. The objective of this work was to characterize indigenous rhizobial strains of saline soils in the Wasteland and Hinterland of Pernambuco State, using yam bean (Pachyrhizus erosus L. Urban) as plant-tramp. Assays had been performed in YMA media and the observed cultivation characteristics of twenty-four isolates had been: change of pH, time of growth, transparency, form, edge, production of exopolysaccharides of the colonies and resistance to salinity. DNA amplification by the PCR technique of the repetitive sequence BOX indicated a high level of genetic and fenotipic diversity between the thirteen indigenous isolates. Comparing cultivation and genetic characteristics of these isolates with nineteen reference strains, indicated that isolates NFB746 and NFB747 had presented high similarity between then and also with the Rhizobium sp. NGR234 (BR2406) and Mesorhizobium ciceri USDA3383 (BR521).The isolated NFB742 possibly belongs to of the same species of the M. ciceri BR521. In relation to the isolated NFB741, the similarity with the Rhizobium tropici IIA CFN299T (BR10016) and Sinorhizobium terangue USDA4894 (BR527) was of 87%. All others isolates had clustered in comparative independent groups when comared to reference lineages. These results are important for diagnosis of new species of native rhizobia in areas where the use of FBN can improve and rehabilitate saline soil using the rizobia-leguminous interaction.

Functional properties of yam bean (Pachyrhizus erosus) starch.

The study was carried out in order to determine and establish the functional characters of starch extracted from yam bean (Pachyrhizus erosus (L) Urban) compared with cassava starch. Yam bean is a tropical tuber legume easily grown and holds a great potential as a new source of starch. Yam bean starch shows functional properties which are peculiar to those of most starch root crops. Gelatinization temperature (53-63 degrees C) and the pasting temperature (64.5 degrees C) are less than those of cereal starch, however, the swelling power is high (54.4 g gel/g dried starch). Yam bean starch paste presents a high viscosity profile, high retrogradation tendency and low stability on cooking. The functional properties of yam bean starch, similar to those of cassava starch, allows yam bean to be used as a potential new source of starch.

Plant and soil characteristics affected by biofertilizers from rocks and organic matter inoculated with diazotrophic bacteria and fungi that produce chitosan

The aim of this study was to evaluate the effectiveness of a mixed biofertilizer with phosphate and potash rocks (PK biofertilizer) combined with an earthworm compound inoculated with free living diazotrophic bacteria and Cunninghamella elegans, fungi that produces chitosan, on cowpea nodulation, biomass yield and nutrient uptake. The effects of some chemical attributes from an acidic soil of the Brazilian Northeast were also studied. The treatments were as follows: a) biofertilizer enriched in N by free living diazotrophic bacteria(NPKB), applying crustaceous chitosan (ChCru) at a rate 2 mg mL -1 ; b) NPKB and ChCru at a rate 4 mg mL -1 ; c) NPKB and ChCru at a rate 6 mg mL -1 ; d) NPKB and fungi chitosan (ChFu, 2 mg mL -1 ); e) NPKB+C. elegans (NPKP); f) NPKB without chitosan; g) mineral fertilizers (NPKF); and h) control without NPK fertilizer and chitosan. Biofertilizer treatments increased cowpea nodules biomass, shoot biomass, and total N, P, and K in the shoots. The largest increase was obtained with ChCru, and the highest rate was obtained with NPKP. Furthermore, biofertilizers reduced soil pH and increased the total N and available P and K. These results reveal the potential of rock biofertilizer mixed with earthworm compound inoculated with free living diazotrophic bacteria and C. elegans (fungi chitosan) for plant production and nutrient uptake. The biofertilizer may be an alternative for NPK fertilization that slows the release of nutrients, favoring longterm soil fertility.

Rendimento da alface e atributos químicos de um Latossolo em função da aplicação de biofertilizantes de rochas com fósforo e potássio

Production of rock biofertilizers is a practical process which reduces energy consumption and increases nutrients availability in soils. A field experiment was carried out applying phosphate biofertilizer (PB) and potash biofertilizer (KB) from rocks plus sulfur with Acidithiobacillus, applied in different rates, comparing with the mineral fertilizers simple superphosphate (SFS) and potassium chloride (KCl), on yield of lettuce (cv. Crespa-Grand Rapids), in two consecutive crops and in soil chemical attributes (pH, and available P and K). A control treatment was added without P and K (P0K0). In the two consecutive crops the biofertilizers BP, BK, and chemical fertilizers SFS and KCl were effective on lettuce yield. In the first crop the best results were obtained with the treatments SFS700 BK90, SFS700 BK60, and in the consecutive crop applying the treatments BP700 BK90, SFS700 BK60 and SFS700 BK90. In the two crops the positive response of the PK biofertilizers and PK mineral fertilizers was evident. Residual effect was observed when the treatment BP1050 BK90 was applied. Soil pH was not affected by application of PK biofertilizers plus worm-compound, increasing available P and K, especially for available P in the consecutive crop. The PK rock biofertilizers, plus worm-compound, may be applied as an alternative to PK mineral soluble fertilizers.

Nutrient uptake by grape in a Brazilian soil affected by rock biofertilizer

PK rock biofertilizers made from rocks and elemental sulphur inoculated with Acidithiobacillus improve yield of many short cycle plants similarly to soluble fertilizers. This study aims to evaluate the potential of PK rock biofertilizers for grape cultivation in the Brazilian San Francisco Valley. Three sources of P and K were compared: (a) soluble fertilizers, (b) biofertilizers plus elemental sulphur inoculated with Acidithiobacillus, and (c) ground phosphate and potash rocks, all at three application rates. A control treatment without P and K fertilization was added. Earthworm compound was applied as N source in all treatments. Grape (Vitis vinifera cv. Italia Pirovano) was cultivated in a dystrophic Planossol (medium texture) at the San Francisco River in the Brazilian Semiarid. P, K, Ca, Mg, S-SO 4 2and Fe concentrations were analyzed in grape leaves and fruits. The results showed adequate leaf contents of S-SO 4 2, K, and Fe with PK biofertilizer application plus earthworm compound, which indicates this may be alternative to soluble fertilizer for grape in soils with low available P and K.

Efeito da fertilização com fósforo, potássio e magnésio em jacatupé infectado com rizóbio em um Latossolo álico

In order to evaluate the effects of phosphorus, potassium and magnesium application on the nutrient absorption and yield of yam bean (Pachyrhizus erosus (L.) Urban), in a Yellow Latosol of the Zona da Mata of Pernambuco State, Brazil, an experiment was carried out using the strain of Bradyrhizobium sp. NFB 450, isolated from yam bean and selected for efficient N2 fixation in previous experiments. Potassium and magnesium were applied in the proportion of 2:1 (K2O:MgO) in increasing levels (0:0, 40:20, 60:30 and 80:40 kg ha-1 of K2O and MgO, respectively), and crescent levels of phosphorus (0, 20, 40, 60 and 80 kg ha-1 of P2O5) were added in the form of triple superphosphate. Maximum dry matter production, total N and total P accumulated were obtained when applying 64 kg ha-1 of P2O5. A significant effect of K2O:MgO levels was observed in relation to the treatment without K and Mg application; nevertheless, higher levels of K2O:MgO decreased dry matter and total N, and increased total P accumulation. Yam bean responded to low levels of P, K and Mg fertilizer, and showed ability in N2 fixation, with great potential for biomass production.

Efeito da calagem e inoculação de sabiá em solo da mata úmida e do semi-árido de Pernambuco

Realizou-se um experimento, usando solo alico da Zona da Mata e do Semi-Arido do Estado de Pernambuco, com o objetivo de avaliar o efeito da calagem (0, 3 e 6 t ha-1) e da inoculacao das estirpes de rizobio: NFB 539, NFB 577 e NFB 578, previamente selecionadas para sabia (Mimosa caesalpiniaefolia) em meio de cultura acido. Adicionaram-se tratamentos sem inoculacao, sem e com adicao de N mineral (100 kg ha-1), para fins comparativos. O experimento seguiu o esquema fatorial 2x3x5, no delineamento em blocos ao acaso, com quatro repeticoes. As plantas foram colhidas 110 dias apos a emergencia (DAE). A inoculacao de rizobio, em todos os niveis de calagem, mostrou efeito significativo nos parâmetros avaliados. No nivel de 3 t ha-1 nao houve efeito da calagem, porem a adicao de 6 t ha-1 de calcario reduziu o peso de materia seca, o N total na parte aerea, a nodulacao e a atividade da nitrogenase. O baixo pH e Al3+ do solo nao prejudicou a fixacao do N2, e o crescimento das plantas que receberam o inoculo. Portanto, torna-se desnecessaria a calagem no cultivo de sabia em solos acidos, quando usadas estirpes selecionadas visando a resistencia a acidez.