Abstract: The bioassay-guided isolation and purification of an
ethyl acetate extract of Aspergillus terreus MC751 led to the
characterization of butyrolactone I as an antidiabetic and antioxidant.
The antidiabetic activity of butyrolactone I was evaluated by α-
glucosidase and α-amylase inhibition assays. Butyrolactone I
demonstrated significant concentration-dependent, mixed-type
inhibitory activity against yeast α-glucosidase with an IC50 of 54μM.
However, the compound exhibited less activity against rat intestinal
α-glucosidase and α-amylase. This is the first report on α-glucosidase
inhibitory activity of butyrolactone I. The antioxidative activity of
butyrolactone I was evaluated based on scavenging effects on 1,1-
diphenyl-2-picrylhydrazyl (DPPH) (IC50 =51 μM) and hydrogen
peroxide (IC50= 141 μM) radicals as well as a reducing power assay.
The results suggest that butyrolactone I is a promising antidiabetic as
well as antioxidant and should be considered for clinical trials.
Abstract: Understanding the cell's large-scale organization is an
interesting task in computational biology. Thus, protein-protein
interactions can reveal important organization and function of the
cell. Here, we investigated the correspondence between protein
interactions and function for the yeast. We obtained the correlations
among the set of proteins. Then these correlations are clustered using
both the hierarchical and biclustering methods. The detailed analyses
of proteins in each cluster were carried out by making use of their
functional annotations. As a result, we found that some functional
classes appear together in almost all biclusters. On the other hand, in
hierarchical clustering, the dominancy of one functional class is
observed. In brief, from interaction data to function, some correlated
results are noticed about the relationship between interaction and
function which might give clues about the organization of the
proteins.
Abstract: β-Glucosidase is an important enzyme for production
of ethanol from lignocellulose. With hydrolytic activity on
cellooligosaccharides, especially cellobiose, β-glucosidase removes
product inhibitory effect on cellulases and forms fermentable sugars.
In this study, β-glucosidase encoding gene (BGL1) from traditional
starter yeast Saccharomycosis fibuligera BMQ908 was cloned and
expressed in Pichia pastoris. BGL1 of S. fibuligera BMQ 908 shared
98% nucleotide homology with the closest GenBank sequence
(M22475) but identity in amino-acid sequences of catalytic domains.
Recombinant plasmid pPICZαA/BGL1 containing the sequence
encoding BGL1 mature protein and α-factor secretion signal was
constructed and transformed into methylotrophic yeast P. pastoris by
electroporation. The recombinant strain produced single extracellular
protein with molecular weight of 120 kDa and cellobiase activity of
60 IU/ml. The optimum pH of the recombinant β-glucosidase was 5.0
and the optimum temperature was 50°C.
Abstract: The biological activity of A. pullulans isolates against
species of the genus Fusarium, bacteria of the genus Azotobacter and
pseudomonads colonizing wheat kernels was evaluated. A field
experiment was carried out in 2009-2011, in north-eastern Poland.
Winter wheat (cv. Bogatka) plants were sprayed with a cell
suspension of A. pullulans at a density of 106 - 108 per cm3 water at
the stem elongation stage and the heading stage. Untreated plants
served as control. The abundance of epiphytic yeasts, bacteria of the
genus Azotobacter, pseudomonads and Fusarium pathogens on wheat
grain was estimated at harvest and after six months’ storage. The
average size of yeast communities was significantly greater on wheat
kernels treated with a cell suspension of A. pullulans, compared with
control samples. In 2010-2011, biological control reduced the
abundance of some species of the genus Fusarium.
Abstract: According to FDA (Food and Drug Administration of the United States), vinegar is definedas a sour liquid containing at least 4 grams acetic acid in 100 cubic centimeter (4% solution of acetic acid) of solution that is produced from sugary materials by alcoholic fermentation. In the base of microbial starters, vinegars could be contained of more than 50 types of volatile and aromatic substances that responsible for their sweet taste and smelling. Recently the vinegar industry has a great proportion in agriculture, food and microbial biotechnology. The acetic acid bacteria are from the family Acetobacteraceae. Regarding to the latest version of Bergy-s Mannual of Systematic Bacteriology that has categorized bacteria in the base of their 16s RNA differences, the most important acetic acid genera are included Acetobacter (genus I), Gluconacetobacter (genus VIII) and Gluconobacter (genus IX). The genus Acetobacter that is primarily used in vinegar manufacturing plants is a gram negative, obligate aerobe coccus or rod shaped bacterium with the size 0.6 - 0.8 X 1.0 - 4.0 μm, nonmotile or motile with peritrichous flagella and catalase positive – oxidase negative biochemically. Some strains are overoxidizer that could convert acetic acid to carbon dioxide and water.In this research one Acetobacter native strain with high acetic acid productivity was isolated from Iranian white – red cherry. We used two specific culture media include Carr medium [yeast extract, 3%; ethanol, 2% (v/v); bromocresol green, 0.002%; agar, 2% and distilled water, 1000 ml], Frateur medium [yeast extract, 10 g/l; CaCO3, 20 g/l; ethanol, 20 g/l; agar, 20 g/l and distilled water, 1000 ml] and an industrial culture medium. In addition to high acetic acid production and high growth rate, this strain had a good tolerance against ethanol concentration that was examined using modified Carr media with 5%, 7% and 9% ethanol concentrations. While the industrial strains of acetic acid bacteria grow in the thermal range of 28 – 30 °C, this strain was adapted for growth in 34 – 36 °C after 96 hours incubation period. These dramatic characteristics suggest a potential biotechnological strain in production of cherry vinegar with a sweet smell and different nutritional properties in comparison to recent vinegar types. The lack of growth after 24, 48 and 72 hours incubation at 34 – 36 °C and the growth after 96 hours indicates a good and fast thermal flexibility of this strain as a significant characteristic of biotechnological and industrial strains.
Abstract: In this research saffron samples were prepared from
farms and sampling was done in four states contain : sampling from
fresh saffron of petal with forceps , sampling from fresh saffron of
petal by hands, sampling from dried sample by warm air in shadow,
sampling from dried sample which dried by dryer. Samples collected
and kept in sterile tubes and containers and carried to laboratory and
maintained until experiment. Microbial experiments were performed
to determine microbial load such as total count, Staphylococcus
aureus, coli form, E.coli, mold and yeast. Results showed that in
picking and drying stages the contamination amount increases in
saffron samples. There was a significant difference between the
microbial load of picked up saffron by forceps and by hands, and
also between dried saffron by warm air in shadow and by dryer.
Abstract: Whole genome duplication (WGD) increased the
number of yeast Saccharomyces cerevisiae chromosomes from 8 to
16. In spite of retention the number of chromosomes in the genome
of this organism after WGD to date, chromosomal rearrangement
events have caused an evolutionary distance between current genome
and its ancestor. Studies under evolutionary-based approaches on
eukaryotic genomes have shown that the rearrangement distance is an
approximable problem. In the case of S. cerevisiae, we describe that
rearrangement distance is accessible by using dedoubled adjacency
graph drawn for 55 large paired chromosomal regions originated
from WGD. Then, we provide a program extracted from a C program
database to draw a dedoubled genome adjacency graph for S.
cerevisiae. From a bioinformatical perspective, using the duplicated
blocks of current genome in S. cerevisiae, we infer that genomic
organization of eukaryotes has the potential to provide valuable
detailed information about their ancestrygenome.
Abstract: Traditionally, Yemini Sidr honey has been reported to
cure liver problems, stomach ulcers, and respiratory disorders. In this
experiment, we evaluated Yemeni Sidr honey for its ability to protect
inflammations caused by acetic acid and formalin -induced writhing,
carrageenan and histamine-induced paw oedema in experimental rat
model. Hyperpyrexia, membrane stabilizing activity, and
phytochemical screening of the honey was also examined. Yemini
Sidr Honey at (100, 200 and 500 mg/kg) exhibited a concentration
dependant inhibition of acetic acid induced and formalin induced
writhing, paw oedema induced by carrageenan & histamine, and
hyperpyrexia induced by brewer's yeast, it also inhibited membrane
stabilizing activity. Phytochemical screenings of the honey reveal the
presence of flavonoids, steroid, alkaloids, saponins and tannins. This
study suggested that Yemeni Sidr honey possess very strong antiinflammatory,
analgesic and antipyretic effects and these effects
would be a result of the phytochemicals present.
Abstract: The objective of this study is to evaluate the
occurrence of fungi in aerobic and anoxic activated sludge from
membrane bioreactors (MBRs). Thirty-six samples of both aerobic
and anoxic activated sludge were taken from 2 MBR treating
domestic wastewater. Over a period of eight months 2 samples from
each plant were taken per month. The samples were prepared for
count and definition of fungi. The obtained data show that, sixty
species belonging to 27 genera were collected from activated sludge
samples under aerobic and anoxic conditions. Regarding to the fungi
definition, under aerobic condition the Geotrichum was found at
(8.8%) followed by Penicillium (75.0%), Yeasts (65.7%) and
Trichoderma (55.5%), while Yeasts (77.1%) Geotrichum
candidumand Penicillium (61.1%) species were the most prevalent in
anoxic activated sludge. The results indicate that activated sludge is
habitat for growth and sporulation of different groups of fungi, both
saprophytic and pathogenic.
Abstract: Saccharomyces cerevisiae (baker-s yeast) can exhibit
sustained oscillations during the operation in a continuous bioreactor
that adversely affects its stability and productivity. Because of
heterogeneous nature of cell populations, the cell population balance
models can be used to capture the dynamic behavior of such cultures.
In this paper an unstructured, segregated model is used which is
based on population balance equation(PBE) and then in order to
simulation, the 4th order Rung-Kutta is used for time dimension and
three methods, finite difference, orthogonal collocation on finite
elements and Galerkin finite element are used for discretization of the
cell mass domain. The results indicate that the orthogonal collocation
on finite element not only is able to predict the oscillating behavior of
the cell culture but also needs much little time for calculations.
Therefore this method is preferred in comparison with other methods.
In the next step two controllers, a globally linearizing control (GLC)
and a conventional proportional-integral (PI) controller are designed
for controlling the total cell mass per unit volume, and performances
of these controllers are compared through simulation. The results
show that although the PI controller has simpler structure, the GLC
has better performance.
Abstract: The dilute acid pretreatment and enzymatic
saccharification of lignocellulosic substrate, cogon grass (Imperata
cylindrical, L.) was optimized prior ethanol fermentation using
simultaneous saccharification and fermentation (SSF) method. The
optimum pretreatment conditions, temperature, sulfuric acid
concentration, and reaction time were evaluated by determining the
maximum sugar yield at constant enzyme loading. Cogon grass, at
10% w/v substrate loading, has optimum pretreatment conditions of
126°C, 0.6% v/v H2SO4, and 20min reaction time. These
pretreatment conditions were used to optimize enzymatic
saccharification using different enzyme combinations. The maximum
saccharification yield of 36.68mg/mL (71.29% reducing sugar) was
obtained using 25FPU/g-cellulose cellulase complex combined with
1.1% w/w of cellobiase, ß-glucosidase, and 0.225% w/w of
hemicellulase complex, after 96 hours of saccharification. Using the
optimum pretreatment and saccharification conditions, SSF of treated
substrates was done at 37°C for 120 hours using industrial yeast
strain HBY3, Saccharomyces cerevisiae. The ethanol yield for cogon
grass at 4% w/w loading was 9.11g/L with 5.74mg/mL total residual
sugar.
Abstract: Sunflower stalks were analysed for chemical
compositions: pentosan 15.84%, holocellulose 70.69%,
alphacellulose 45.74%, glucose 27.10% and xylose 7.69% based on
dry weight of 100-g raw material. The most optimum condition for
steam explosion pretreatment was as follows. Sunflower stalks were
cut into small pieces and soaked in 0.02 M H2SO4 for overnight.
After that, they were steam exploded at 207 C and 21 kg/cm2 for 3
minutes to fractionate cellulose, hemicellulose and lignin. The
resulting hydrolysate, containing hemicellulose, and cellulose pulp
contained xylose sugar at 2.53% and 7.00%, respectively.The pulp
was further subjected to enzymatic saccharification at 50 C, pH 4.8 citrate buffer) with pulp/buffer 6% (w/w)and Celluclast 1.5L/pulp
2.67% (w/w) to obtain single glucose with maximum yield 11.97%.
After fixed-bed fermentation under optimum condition using
conventional yeast mixtures to produce bioethanol, it indicated
maximum ethanol yield of 0.028 g/100 g sunflower stalk.
Abstract: Plackett-Burman statistical screening of media
constituents and operational conditions for extracellular lipase
production from isolate Trichoderma viride has been carried out in
submerged fermentation. This statistical design is used in the early
stages of experimentation to screen out unimportant factors from a
large number of possible factors. This design involves screening of
up to 'n-1' variables in just 'n' number of experiments. Regression
coefficients and t-values were calculated by subjecting the
experimental data to statistical analysis using Minitab version 15.
The effects of nine process variables were studied in twelve
experimental trials. Maximum lipase activity of 7.83 μmol /ml /min
was obtained in the 6th trail. Pareto chart illustrates the order of
significance of the variables affecting the lipase production. The
present study concludes that the most significant variables affecting
lipase production were found to be palm oil, yeast extract, K2HPO4,
MgSO4 and CaCl2.
Abstract: The objective of this research is to study of microbial lipid production by locally photosynthetic microalgae and oleaginous yeast via integrated cultivation technique using CO2 emissions from yeast fermentation. A maximum specific growth rate of Chlorella sp. KKU-S2 of 0.284 (1/d) was obtained under an integrated cultivation and a maximum lipid yield of 1.339g/L was found after cultivation for 5 days, while 0.969g/L of lipid yield was obtained after day 6 of cultivation time by using CO2 from air. A high value of volumetric lipid production rate (QP, 0.223 g/L/d), specific product yield (YP/X, 0.194), volumetric cell mass production rate (QX, 1.153 g/L/d) were found by using ambient air CO2 coupled with CO2 emissions from yeast fermentation. Overall lipid yield of 8.33 g/L was obtained (1.339 g/L of Chlorella sp. KKU-S2 and 7.06g/L of T. maleeae Y30) while low lipid yield of 0.969g/L was found using non-integrated cultivation technique. To our knowledge this is the unique report about the lipid production from locally microalgae Chlorella sp. KKU-S2 and yeast T. maleeae Y30 in an integrated technique to improve the biomass and lipid yield by using CO2 emissions from yeast fermentation.