scholarly journals Production of glucose and fructose syrups from cassava (Manihot esculenta Crantz) starch using enzymes produced by microorganisms isolated from Brazilian Cerrado soil

2010 ◽  
Vol 30 (1) ◽  
pp. 213-217 ◽  
Author(s):  
Roberto do Nascimento Silva ◽  
Fábio Pereira Quintino ◽  
Valdirene Neves Monteiro ◽  
Eduardo Ramirez Asquieri

The high demands for sugars and the development of enzymatic technology have increased the production of sweeteners, especially for glucose and fructose syrups. This work describe a technology for glucose and fructose syrups from Brazilian cassava starch using enzymes produced by soil microrganisms isolated from the Brazilian Cerrado soil. Firstly, Aspergillus niger and Streptomyces sp. were isolated from the soil and used as glucoamylase (GA) and glucose isomerase (GI) producer sources. After characterization, GA and GI exhibited optimum pH 4.5 and 8.0, respectively. GA showed maximum activity at 60 ºC and GI at 85 ºC. GA and GI retained 65 and 80%, respectively, of initial activity after 180 minutes of incubation at 60 ºC. The kinetic parameters Km and Vmáx were 0.476 (mg.mL-1) and 8.58 (µmol/minute) for GA and 0.082 (M) and 48.20 (µmol/minute) for GI. The maximum glucose syrups production occurred after 24 hours of reaction with a 98% yield. The production of fructose syrups with 42% (w/v) was reached after 96 hours of reaction.

2011 ◽  
Vol 22 (4) ◽  
pp. 452-468 ◽  
Author(s):  
Christian Isendahl

AbstractOwing to poor preservation of organic remains in humid environments, direct evidence of early manioc (Manihot esculenta Crantz) cultivation is exceptionally rare in datable archaeological contexts. Recent research summarized here offers new insights into the spatio-temporal framework of the initial domestication and early spread of manioc in the Neotropics. Integrating evidence from comparative plant genetics and paleoethnobotanic starch analysis to contribute to the archaeology of manioc origins, this review finds that (1) the strongest candidate for the botanical origin of domesticated manioc—the wild progenitor of the root crop—is the species Manihot esculenta subspecies flabellifolia (Pohl) Ciferri; (2) the geographical origin of manioc—the biome in which the progenitor evolved—is most likely in the savannas, the Brazilian Cerrado, to the south of the Amazon rainforest; (3) the Cerrado is also, in our best estimate, the region of agricultural origin of initial cultivation; (4) domesticated manioc had spread from the agricultural origin by the early Holocene, possibly as early as 10,000 years ago, but certainly by 7000 B.C.; and (5) domesticated manioc was a readily available plant in most habitats of the Neotropics by the mid-Holocene, at least some 6500 years ago.


2007 ◽  
Vol 78 (4) ◽  
pp. 1212-1220 ◽  
Author(s):  
F. Martínez-Bustos ◽  
M. López-Soto ◽  
E. San Martín-Martínez ◽  
J.J. Zazueta-Morales ◽  
J.J. Velez-Medina

2013 ◽  
Vol 5 (1) ◽  
pp. 50
Author(s):  
Kellem Ângela Oliveira de Sousa ◽  
José Fábio França de Orlanda ◽  
Gustavo De Andrade Bezerra ◽  
Thatyane Pereira De Sousa

RESUMO: O presente trabalho objetivou avaliar a capacidade antimicrobiana in vitro, de diferentes extratos de fungos endofíticos, como alternativa no biocontrole de Fusarium oxysporum f.sp. lycopersici. Foram obtidos oito isolados endofíticos de plantas do Cerrado Maranhense e de interesse econômico, a saber: aroeira (Myracrodruon urundeuva Allemão), jenipapo (Genipa americana L.), milho (Zea Mays L.), mandioca (Manihot esculenta Crantz), vinagreira (Hibiscus sabidariffa L.) e graviola (Annona muricata L.). Os isolados endofiticos das espécies foram identificados em Aspergillus niger e Penicillium italicum, com características morfológicas distintas entre as colônias e todos os isolados endofíticos verificou-se crescimento mediano. Para a atividade antimicrobiana, foi realizada a extração dos metabólitos dos isolados endofiticos com os solventes: Acetato de Etila, Clorofórmio e Diclorometano, posteriormente realizado o bioensaio através do confronto direto do antagonista (endófito) sobre o Fusarium Oxysporum f.sp. lycopersici, raça 1, pelo método de difusão em ágar. Os extratos dos isolados endofíticos obtidos do solvente Clorofórmio apresentaram capacidade inibitória, assim interferindo no crescimento do Fusarium oxysporum f. sp. lycopersici raça. Que foram provenientes do caule milho (II) e de jenipapo, com diâmetros de 13mm e 11mm, respectivamente, os outros extratos dos isolados apresentaram halos de inibição inferior. PALAVRAS-CHAVE: antibiose, controle biológico, fitopatógeno.


2011 ◽  
Vol 63 (10) ◽  
pp. 595-603 ◽  
Author(s):  
Renata Baraldi de Pauli ◽  
Leda Battestin Quast ◽  
Ivo Mottin Demiate ◽  
Lyssa Setsuko Sakanaka

2014 ◽  
Vol 12 (1) ◽  
pp. 587-596 ◽  
Author(s):  
J. Rodriguez ◽  
F. Soria ◽  
H. Geronazzo ◽  
H. Destefanis

Abstract The α-amylase from Aspergillus oryzae was immobilized covalently onto expanded perlite (EP) and modified EP by treatment with TiO2 (EP-TiO2), dye HE3B (EP-HE3B) polyethylene terephthalate (PET)-hydrazide (EP-PET) and magnetite (EP-magnetite). The modified EP was characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The supports were functionalized with aminopropyltriethoxysilane (APTES) and glutaraldehyde (GA). The optimum pH for free and immobilized α-amylase was 5.5. Temperature of maximum activity for free enzyme and immobilized enzyme on EP-HE3B was 50°C. The immobilized enzyme in EP-APTES this value was 55°C. The immobilized α-amylase in EP-APTES and EP-HE3B-APTES exhibited better thermostability than free enzyme. The immobilized derivatives showed moderate operational stability by retaining 50% of initial activity after seven successive reuses.


2017 ◽  
Vol 11 (12) ◽  
pp. 403-407
Author(s):  
K. NKERE Chukwuemeka ◽  
IKPEAMA Ahamefula ◽  
O. UZOECHI Amarachukwu ◽  
N. A. MBANASO Egbichi

2018 ◽  
Vol 63 (1) ◽  
pp. 11-17
Author(s):  
Hargono Hargono ◽  
Andri Cahyo Kumoro ◽  
Bakti Jos

The kinetics and inhibitory effects of cyanide on the granular starch hydrolyzing enzyme (GSHE) activity during hydrolysis of cassava (Manihot esculenta Crantz) starch at low temperature were studied. The substrates included native cassava starch at various concentrations (100-400 g/L) and native cassava starches with added cyanide at various concentrations (50-150 mg/kg), while the concentration of enzyme was 1.5% (w/w). A decrease in reducing sugar concentration during hydrolysis of cassava starch indicated that the cyanide reduced the enzyme activity. Lineweaver-Burk plot of Michaelis-Menten equation was used to study the inhibition kinetics. The maximum velocity (Vmax) value was higher for native cassava starch than that of native cassava starch with added cyanides. The presence of cyanide was found to reduce the Vmax values. No significant different of the saturation constant (Km) value between native cassava starch and native cassava starch with added cyanides was observed. Based on the inhibition type analysis, the effect of cyanide in the cassava starch can be classified as a noncompetitive inhibition, with the Ki value of 0.33 mg/L.


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