145 research outputs found
Xylanase production by Aspergillus niger ANL 301 using agro - wastes
Xylanase production by wild-type Aspergillus niger ANL301, newly isolated from wood-waste, was
monitored at 24 h intervals for a period 168 h in media containing different carbon sources. The carbon
sources were oat-spelt xylan (Fluka) and three agro-wastes (sawdust, sugarcane pulp and wheat bran).
Highest xylanase activity of 6.47 units/mL was obtained at 96 h in media containing wheat bran as sole
carbon source. Maximum activity value for the media containing sugarcane pulp was 0.95 units/mL
obtained also at 96 h. Sawdust and oat spelt xylan gave the peak enzyme activities of 0.65 and 0.80
units/mL respectively at 120 h. High protein yield was obtained in media containing the agro-wastes,
with wheat bran giving the highest value of 1.14 mg/mL at 96 h. The maximum specific xylanase
activities were 3.86, 3.37, 5.69, and 9.36 units/ mg protein for sawdust, sugarcane pulp, wheat bran and
oat spelt xylan, respectively. Out of the three agro-wastes used in this study, wheat bran holds greatest
promise for low cost production of the xylanase enzyme
Agro-waste: a potential fermentation substrate for Penicillium chrysogenum
Common agro-wastes found in Lagos, Nigeria (cassava shavings, corncob, sawdust, and sugarcane
pulp) were compared with glucose and lactose as fermentation substrates for Penicillium chrysogenum
PCL501. Cassava shavings significantly (P<0.001) produced the highest amount of mycelia weight (0.43 ±
0.02 mg/ml) than all the other substrates. This was followed by corncob with peak mycelia weight of 0.33 ±
0.02 mg/ml. Peak mycelia weight of 0.27 ± 0.01 mg/ml was equally obtained with glucose and sugarcane pulp
whereas lactose gave a slightly lower peak of 0.25 ± 0.01 mg/ml. Sawdust gave the least mycelia weight of
0.13 ± 0.01 mg/ml. Total sugar content of all the culture media steadily decreased as fungal growth progressed
indicating that the organism utilized carbohydrates for growth and mycelia formation. Cultures containing
cassava shavings and sawdust gave high protein peaks of 0.84 ± 0.05 and 0.65 ± 0.03 mg/ml respectively.
Cultures containing corncob, glucose, lactose and sugarcane pulp yielded lower protein peaks of 0.37 ± 0.02,
0.30 ± 0.02, 0.24 ± 0.02 and 0.18 ± 0.01 mg/ml respectively. The results suggest that cassava shavings,
corncob and sugarcane pulp could serve as cheap fermentation substrates for the growth of the fungus. Of all
the substrates investigated, cassava shavings have the best potential to serve as substrate for fermentation by
Penicillium chrysogenum PCL501.
© 2009 International Formulae Group. All rights reserved
Sulphuric Acid Corrosion of Mild Steel in Leave Extracts of Cnidoscolus aconitifolius Plant
Alkaloid and nonalkaloids extracts of Cnidoscolus aconitifolius leaves is reported as corrosion inhibitor of mild steel in HCl. Conventional weight loss measurements and Tafel polarization techniques are employed to study the effect on mild steel corrosion in H2SO4 solutions. The weight loss result revealed that both plant extracts are excellent corrosion inhibitors. Electrochemical polarization data revealed that mixed mode of inhibition. The increase in %IE with change in concentration of the extracts suggests the strong adsorption of active molecules leading to the formation of a protective layer on the mild steel surface. It was found that adsorption of both leaf extracts followed Langmuir adsorption isotherm model. Keywords: Weight loss, Langmuir isotherm, activation energy, corrosion current density, inhibition efficiency, Cnidoscolus aconitifolius
Xylanase production by Penicillium chrysogenum (PCL501) fermented on cellulosic wastes
Xylanase production by Penicillium chrysogenum PCL501, newly isolated from wood-wastes, was
monitored at 24 h intervals for a period 168 h in media containing four different carbon sources (oatspelt
xylan, wheat bran, sawdust, and sugarcane pulp). The highest xylanase activity of 6.47 Units mL-1
was obtained at 96 h in media containing wheat bran whereas media containing sugarcane pulp gave a
peak value of 1.39 Units mL-1 at 144 h. Sawdust and xylan gave a peak xylanase activity of 1.35 and 0.79
Units mL-1 respectively at 120 h. Maximum protein released in xylan-containing media was 0.38 mg mL-1.
Higher protein yield was obtained in media containing the agro-wastes, with wheat bran giving the
highest value of 1.14 mg mL-1. The maximum specific xylanase activities were 2.59, 8.52, 16.06, and 9.36
Units mg Protein -1 for sawdust, sugarcane pulp, wheat bran and xylan respectively. Out of the three
agro-wastes used in this study, wheat bran holds the greatest promise for cost-effective production of
the xylanase enzyme. The carbon source is the highest inducer of the enzyme in the fungus
Effect of carbon sources on cellulase (EC 3. 2. 1. 4) production by Penicillium chrysogenum PCL501
The effects of glucose, crystalline cellulose and sawdust of Mitragyna cilata on the growth and cellulase
production, inferred from cellulase (EC 3. 2. 1. 4) activity, of Penicillium chrysogenum PCL501 was
determined. Glucose-containing media gave the highest mycelia weight of 1.78 mg mL-1 in 120 h of
incubation. This is about 3.5 – 4.5 times the maximum weights of 0.51 and 0.40 mg mL-1 respectively
obtained from the cultures containing cellulose and sawdust. The cultures containing crystalline
cellulose and sawdust produced extracellular protein with cellulase (EC 3. 2. 1. 4) activity whereas
glucose-containing cultures yielded very low protein and no significant cellulase activity. Maximum
protein content of 0.02, 0.13 and 0.46 mg mL-1 respectively were obtained from the cultures containing
glucose, cellulose and sawdust. Peak cellulase activity values of 100.0 and 92.2 Units L-1 respectively
were obtained for the cultures containing cellulose and sawdust. There is a correlation between the
protein released and cellulase activity of the culture filtrates. P. chrysogenum PCL501 produces
extracellular proteins with significant cellulase activity in media containing cellulose and sawdust but
not in glucose-containing medium. Sawdust is indicated as a good inducer of cellulase activity in the
organism. The waste cellulosic material can be used as low-cost carbon source for commercial
cellulase production
Plant Waste Hydrolysis by Extracellular Enzymes of Aspergillus niger and Penicillium chrysogenum: Effect of Ammonia Pretreatment
Aspergillus niger (ANL301) and Penicillium chrysogenum (PCL 501) cultured in basal media with cellulose as sole
carbon source yielded extracellular enzymes which partially hydrolyzed sawdust and sugarcane pulp into simple
sugars. Pre-treatment of sawdust by ammonium hydroxide steeping increased the yield of simple sugars. The reducing
sugars released from the pretreated sawdust by the crude enzymes of A. niger (ANL301) and P. chrysogenum
(PCL 501) were 3.58% and 7.02% of the total hydrolysable sugars respectively. This is in contrast to the 0.92% and
1.02% of the total hydrolysable sugars released respectively by the enzymes of A. niger (ANL301) and P. chrysogenum
(PCL 501) from the non-pretreated sawdust. Enzymatic hydrolysis of sugarcane pulp by the crude enzymes
was not significantly affected by ammonia pre-treatment. Reducing sugars released from non-pretreated sugarcane
pulp by the crude enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) were respectively 4.17% and
5.08% of the total hydrolysable sugars
Potentiality of Diethylamine as Agent of Deproteination and Deacetylation in the Extraction of Chitosan from Scylla serrata Shell
The potentiality of diethylamine as deproteination and deacetylation agent in the extraction of chitosan from Scylla serrata (giant mud crab) shell was investigated. The aim was to find an alternative agent to inorganic alkalis as possible replacement for use in the production of high quality chitosan with the right stability. Pretreatment of the shell was carried out and followed by demineralization using hydrochloric acid. Diethylamine was used for deproteination and deacetylation by modifying some published protocols. Moisture, ash, fat and protein contents of the extracts were determined using their respective standard methods. Fourier Transform Infrared (FTIR) technique was used for spectroscopic analysis. Scylla serrata shell was composed of 14.25% protein, 32.84% mineral (CaCO3), 31.52% chitin and 21.39% chitosan. Moisture, ash, fat and protein contents of chitin extracted from Scylla serrata shell were 2.35%, 3.03%, 1.79% and 3.85% respectively while those of chitosan were 1.65%, 3.84%, 0.53% and 2.80% respectively. Degree of deacetylation (DDA) and carbon to nitrogen ratio were 69.24% and 5.67 respectively. FTIR spectra of the extracted chitin and chitosan from Scylla serrata showed the presence of some active compounds of carbonyl, amide, amine and hydroxyl groups. However, CH3 waging along chain (952 cm-1), CO stretching at 1026 cm-1 and 1073 cm-1, and amide II band (1563 cm-1) were not found in the extracted chitin while HPO42- and amide III were also not found in the extracted chitosan. These moieties were present in the standard chitin and chitosan respectively. This study has shown that diethylamine (organic base) has great potential as agent of deproteination and deacetylation in the extraction of chitosan from Scylla serrata. Consequently, academic activity in the area of investigation of the stability of the extracted chitosan from Scylla serrata using diethylamine as deproteination and deacetylation agent is strongly recommended. Keywords: Diethylamine, deproteination, deacetylation, chitin and chitosan, Scylla serrata shell. DOI: 10.7176/CMR/12-7-07 Publication date:October 31st 2020
Pattern of Blood Pressure Indices among the Residents of a Rural Community in South East Nigeria
Cardiovascular diseases (CVDs) are the main causes of death in industrialized countries, and are significant causes of morbidity and mortality in sub-Saharan Africa. Hypertension is the most common cardiovascular disease in Nigerians, and the risk of CVD associated with hypertension is independent of other risk factors. Despite the high level of awareness of its presence in the developed countries, the level of control is still poor. CVDs tend to be commoner in urban settlements, and it has been hypothesized that rural sub-Saharan Africa is at an early stage of epidemiological transition from communicable to non-communicable diseases (NCD) because of the gradual adoption of unhealthy lifestyles. This study aimed at describing the pattern of blood pressure indices among the hypertensive residents of a rural community in South East Nigeria. A total of 858 individuals comprising 247 males and 611 females took part in the study. 46.4% of the subjects had hypertension. Hypertension was commoner in the males (50.2% vs. 44.8%) (χ2(1) = 1.484; P = 0.223). The males were significantly older and heavier than the females while the females had higher mean values of BMI and WC. The prevalence of hypertension is becoming alarmingly high in the rural communities of sub-Saharan Africa
Pectinolytic activity of wild-type filamentous fungi fermented on agro-wastes
Five filamentous fungi (Aspergillus clavatus, Aspergillus niger, Fusarium sp., Penicillum chrysogenum
and Trichoderma sp.) isolated from agrowaste samples in Lagos metropolis, Nigeria, depolymerized
citrus pectin. Best pectolytic activity, as indicated by the diameter of clear, hydrolyzed zones on the
medium plates containing commercial citrus pectin as sole carbon source, was obtained with A. niger,
closely followed by P. chrysogenum. The two fungi also produced pectinases with different agrowastes
(pineapple peel, orange peels, sawdust, sugarcane pulps and wheat bran) as the sole carbon source.
The highest pectinase activity by both fungi was produce with wheat bran as the sole carbon source.
Peak pectinase activity of 350.28 ± 2.82 and 478.25 ± 3.04 IU mg-1 protein was respectively obtained by
submerged fermentation (SmF) at 48 h for A. niger and P.chrysogenum in media containing wheat bran
as the sole carbon source. Solid-state fermentation (SSF) yielded higher levels of pectinase activity
than the SmF. The strains of A. niger and P. chrysogenum have good prospect for pectinase
production. Wheat bran is a good low-cost fermentation substrate for pectinase production by the
investigated fungi
Prevalence of Cardiovascular Risk Factors in the Middle-Aged and Elderly Population of a Nigerian Rural Community
Cardiovascular diseases (CVDs) causes of worldwide preventable morbidity and mortality. CVDs are a leading cause of mortality and morbidity in developing countries, and rates are expected to rise over the next few decades. The prevalence of CVD risk factors is dramatically increasing in low-and middle-income African countries, particularly in urban areas. We carried out a cross-sectional population-based survey in Imezi-Owa, a rural community in South East Nigeria to estimate the prevalence of major cardiovascular risk factors in both men and women aged 40–70 years. A total of 858 individuals made up of 247 (28.8%) males and 611 (71.2%) females were recruited. The mean age of the subjects was 59.8 ± 9.9 years. The prevalence of the different cardiovascular risk factors among the 858 subjects was as follows: hypertension 398 (46.4%) subjects, generalized obesity as determined by BMI 257 (30%) subjects, abdominal obesity 266 (31%) subjects, dysglycaemia 38 (4.4%) subjects and hypercholesterolaemia 32 (3.7%) subjects. Prevalence of hypertension and dysglycaemia was higher in men while the others were higher in women. Only hypertension (P = .117) and hypercholesterolaemia (P = .183) did not reveal any significant association with gender. Prevalence of CVD risk factors was highest in subjects aged 65 to 70 years
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