Abstract: Food contamination occurs during post process
handling. This leads to spoilage and growth of pathogenic
microorganisms in the food, thereby reducing its shelf life or
spreading of food borne diseases. Several methods are tried and one
of which is use of antimicrobial packaging. Here, papain, a protease
enzyme, is covalently immobilized with the help of glutarldehyde on
polyurethane and used as a food wrap to protect food from microbial
contamination. Covalent immobilization of papain was achieved at a
pH of 7.4; temperature of 4°C; glutaraldehyde concentration of 0.5%;
incubation time of 24h; and 50mg of papain. The formation of -C=Nobserved
in the Fourier transform infrared spectrum confirmed the
immobilization of the enzyme on the polymer. Immobilized enzyme
retained higher activity than the native free enzyme. The modified
polyurethane showed better reduction of Staphylococcus aureus
biofilm than bare polymer film (eight folds reduction in live colonies,
two times reduction in protein and 6 times reduction in
carbohydrates). The efficacy of this was studied by wrapping it over
S. aureus contaminated cottage cheese (paneer) and cheese and
stored at a temperature of 4°C for 7days. The modified film reduced
the bacterial contamination by eight folds when compared to the bare
film. FTIR also indicated reduction in lipids, sugars and proteins in
the biofilm.
Abstract: The objective of the study was to select the survival of
probiotic strains when exposed to acidic and bile salts condition. Four
probiotic strains Lactobacillus casei subsp. rhamnosus TISTR 047,
Lactobacillus casei TISTR 1500, Lactobacillus acidophilus TISTR
1338 and Lactobacillus plantarum TISTR 1465 were cultured in
MRS broth and incubated at 35ºC for 15 hours before being inoculated
into acidic condition 5 M HCl, pH 2 for 2 hours and bile salt 0.3%,
pH 5.8 for 8 hour. The survived probiotics were counted in MRS agar.
Among four stains, Lactobacillus casei subsp. rhamnosus TISTR 047
was the highest tolerance specie. Lactobacillus casei subsp.
rhamnosus TISTR 047 reduced 6.74±0.07 log CFU/ml after growing
in acid and 5.52±0.05 log CFU/ml after growing in bile salt. Then,
double emulsion of microorganisms was chosen to encapsulate before
spray drying. Spray drying was done with the inlet temperature 170ºC
and outlet temperature 80ºC. The results showed that the survival of
encapsulated Lactobacillus casei subsp. rhamnosus TISTR 047 after
spray drying decreased from 9.63 ± 0.32 to 8.31 ± 0.11 log CFU/ml
comparing with non-encapsulated, 9.63 ± 0.32 to 4.06 ± 0.08 log
CFU/ml. Therefore, Lactobacillus casei subsp. rhamnosus TISTR 047
would be able to survive in gastrointestinal and spray drying condition.
Abstract: Pollution of the Klip River has caused
microorganisms inhabiting it to develop protective survival
mechanisms. This study isolated and characterized the heavy metal
resistant bacteria in the Klip River. Water and sediment samples were
collected from six sites along the course of the river. The pH,
turbidity, salinity, temperature and dissolved oxygen were measured
in-situ. The concentrations of six heavy metals (Cd, Cu, Fe, Ni, Pb
and Zn) of the water samples were determined by atomic absorption
spectroscopy. Biochemical and antibiotic profiles of the isolates were
assessed using the API 20E® and Kirby Bauer Method. Growth
studies were carried out using spectrophotometric methods. The
isolates were identified using 16SrDNA sequencing. The uppermost
part of the Klip River with the lowest pH had the highest levels of
heavy metals. Turbidity, salinity and specific conductivity increased
measurably at Site 4 (Henley on Klip Weir). MIC tests showed that
16 isolates exhibited high iron and lead resistance. Antibiotic
susceptibility tests revealed that the isolates exhibited multitolerances
to drugs such as Tetracycline, Ampicillin, and
Amoxicillin.
Abstract: The mineral bioflotation represents a viable
alternative for the evaluation of new processes benefit alternative.
The adsorption bacteria on minerals surfaces will depend mainly on
the type of the microorganism as well as of the studied mineral
surface. In the current study, adhesion of S. carnosus on coal was
studied. Several methods were used as: DRX, Fourier Transform
Infra-Red (FTIR) adhesion isotherms and kinetic. The main goal is to
recovery of organic matter by the microflotation process on coal
particles with biological reagent (S. carnosus). Adhesion tests
revealed that adhesion took place after of 8 h at pH 9. The results
suggest that the adhesion of bacteria to solid substrates can be
considered an abiotic physicochemical process that is consequently
governed by bacterial surface properties such as their specific surface
area, hydrophobicity and surface functionalities. The greatest coal
fine flotability was of 75%, after 5 min of flotation.
Abstract: Natural antimicrobials are used to preserve foods that
can be found in plants, animals, and microorganisms. Antimicrobial
substances are natural or artificial agents that produced by
microorganisms or obtained semi/total chemical synthesis are used at
low concentrations to inhibit the growth of other microorganisms.
Food borne pathogens and spoilage microorganisms are inactivated
by the use of antagonistic microorganisms and their metabolites.
Yeasts can produce toxic proteins or glycoproteins (toxins) that cause
inhibition of sensitive bacteria and yeast species. Antimicrobial
substance producing phenotypes belonging different yeast genus
were isolated from different sources. Toxins secreted by many yeast
strains inhibiting the growth of other yeast strains. These strains show
antimicrobial activity, inhibiting the growth of mold and bacteria.
The effect of antimicrobial agents produced by yeasts can be
extremely fast, and therefore may be used in various treatment
procedures. Rapid inhibition of microorganisms is possibly caused by
microbial cell membrane lipopolysaccharide binding and in
activation (neutralization) effect. Antimicrobial agents inhibit the
target cells via different mechanisms of action.
Abstract: Among agricultural residues, sugarcane bagasse is one of the most convincing raw materials for the production of bioethanol due to its availability, and low cost through enzymatic hydrolysis and yeast fermentation. A pretreatment step is needed to enhance the enzymatic step. In this study, sugarcane bagasse (SCB), one of the most abundant agricultural residues in Thailand, was pretreated biologically with various microorganisms of white-rot fungus—Phanerochaete sordid (SK 7), Cellulomonas sp. (TISTR 784), and strain A 002 (Bacillus subtilis isolated from Thai higher termites). All samples with various microbial pretreatments were further hydrolyzed enzymatically by a commercial enzyme obtained from Aspergillus niger. The results showed that the pretreatment with the white-rot fungus gave the highest glucose concentration around two-fold higher when compared with the others.
Abstract: The aim of this study was to determine the antimicrobial effect of Helichrysum arenarium L. essential oil in "in-vitro" condition on the growth of seven microbial species including Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Saccharomyces cereviciae, Candida albicans, Aspergillus flavus and Aspergillus parasiticus using micro-dilution method. The minimum inhibitory concentration (MIC) and minimum bactericidal or fungicidal concentration (MBC, MFC) were determined for the essential oil at ten concentrations. Finally, the sensitivity of tested microbes to essential oil of H. arenarium was investigated. Results showed that Bacillus subtilis (MIC=781.25 and MBC=6250 µg/ml) was more resistance than two other bacterial species. Among the tested yeasts, Saccharomyces cereviciae (MIC=97.65 and MFC=781.25 µg/ml) was more sensitive than Candida albicans while among the fungal species, growth of Aspergillus parasiticus inhibited at lower concentration of oil than the Aspergillus flavus. The extracted essential oil exhibited the same MIC value in the liquid medium against all fungal strains (48.82 µg/ml), while different activity against A. flavus and A. parasiticus was observed in this medium with MFC values of 6250 and 390.625µg/ml, respectively. The results of the present study indicated that Helichrysum arenarium L essential oil had significant (P
Abstract: Endophytic microorganisms are presented in plants of different families growing in the foothills and piedmont plains of Trans-Ili Alatau. It was found that the maximum number of endophytic micromycetes is typical to the Fabaceae family. The number of microscopic fungi in the roots reached (145.9±5.9)×103 CFU/g of plant tissue; yeasts - (79.8±3.5)×102 CFU/g of plant tissue. Basically, endophytic microscopic fungi are typical for underground parts of plants. In contrast, yeasts more infected aboveground parts of plants. Small amount of micromycetes is typical to inflorescence and fruits. Antagonistic activity of selected micromycetes against Fusarium graminearum, Cladosporium sp., Phytophtora infestans and Botrytis cinerea phytopathogens was detected. Strains with a broad, narrow and limited range of action were identified. For further investigations Rh2 and T7 strains were selected, they are characterized by a broad spectrum of fungicidal activity and they formed the large inhibition zones against phytopathogens. Active antagonists are attributed to the Rhodotorula mucilaginosa and Beauveria bassiana species.
Abstract: Anaerobic modeling is a useful tool to describe and
simulate the condition and behaviour of anaerobic treatment units for
better effluent quality and biogas generation. The present
investigation deals with the anaerobic treatment of brewery
wastewater with varying organic loads. The chemical oxygen demand
(COD) and total suspended solids (TSS) of the influent and effluent
of the bioreactor were determined at various retention times to
generate data for kinetic coefficients. The bio-kinetic coefficients in
the modified Stover–Kincannon kinetic and methane generation
models were determined to study the performance of anaerobic
digestion process. At steady-state, the determination of the kinetic
coefficient (K), the endogenous decay coefficient (Kd), the maximum
growth rate of microorganisms (μmax), the growth yield coefficient
(Y), ultimate methane yield (Bo), maximum utilization rate constant
Umax and the saturation constant (KB) in the model were calculated to
be 0.046 g/g COD, 0.083 (d¯¹), 0.117 (d-¹), 0.357 g/g, 0.516 (L
CH4/gCODadded), 18.51 (g/L/day) and 13.64 (g/L/day) respectively.
The outcome of this study will help in simulation of anaerobic model
to predict usable methane and good effluent quality during the
treatment of industrial wastewater. Thus, this will protect the
environment, conserve natural resources, saves time and reduce cost
incur by the industries for the discharge of untreated or partially
treated wastewater. It will also contribute to a sustainable long-term
clean development mechanism for the optimization of the methane
produced from anaerobic degradation of waste in a close system.
Abstract: Concrete durability as an important engineering property of concrete, determining the service life of concrete structures very significantly, can be threatened and even lost due to the interactions of concrete with external environment. Bio-corrosion process caused by presence and activities of microorganisms producing sulphuric acid is a special type of sulphate deterioration of concrete materials. The effects of sulphur-oxidizing bacteria Acidithiobacillus thiooxidans on various concrete samples, based on silica fume and zeolite, were investigated in laboratory during 180 days. A laboratory study was conducted to compare the performance of concrete samples in terms of the concrete deterioration influenced by the leaching of calcium and silicon compounds from the cement matrix. The changes in the elemental concentrations of calcium and silicon in both solid samples and liquid leachates were measured by using X – ray fluorescence method. Experimental studies confirmed the silica fume based concrete samples were found out to have the best performance in terms of both silicon and calcium ions leaching.
Abstract: Mastitis is one of the most economic disease affecting dairy cows worldwide. Its classic diagnosis using bacterial culture and biochemical findings is a difficult and prolonged method. In this research, using of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) permitted identification of different microorganisms with high accuracy and rapidity (only 24 hours for microbial growth and analysis). During the application of MALDI-TOF MS, one hundred twenty strains of Staphylococcus and Streptococcus species isolated from milk of cows affected by clinical and subclinical mastitis were identified, and the results were compared with those obtained by traditional methods as API and VITEK 2 Systems. 37 of totality 39 strains (~95%) of Staphylococcus aureus (S. aureus) were exactly detected by MALDI TOF MS and then confirmed by a nuc-based PCR technique, whereas accurate identification was observed in 100% (50 isolates) of the coagulase negative staphylococci (CNS) and Streptococcus agalactiae (31 isolates). In brief, our results demonstrated that MALDI-TOF MS is a fast and truthful technique which has the capability to replace conventional identification of several bacterial strains usually isolated in clinical laboratories of microbiology.
Abstract: Yoghurt is a fermented milk product. The process of making yogurt involves fermenting milk with live and active bacterial cultures by adding bacteria directly to the dairy product. It is usually made with a culture of Lactobacillus sp. (L. acidophilus or L. bulgaricus) and Streptococcus thermophilus. Many people like to eat it plain or flavored and it's also use as ingredient in many dishes. Yogurt is rich in nutrients including the microorganism which have important role in balancing the digestion and absorption of the boy.Consumers will benefit from lactic acid bacteria more or less depending on the amount of bacteria that lives in yogurt while eating. When purchasing yogurt, consumers should always check the label for live cultures. Yoghurt must keep in refrigerator at 4°C for up to ten days. After this amount of time, the cultures often become weak. This research studied freezing dry yogurt storage by monitoring on the survival of microorganisms when stored at different temperatures. At 300C, representative room temperature of country in equator zone, number of lactic acid bacteria reduced 4 log cycles in 10 week. At 400C, representative temperature in summer of country in equator zone, number of lactic acid bacteria also dropped 4 log cycle in 10 week, similar as storage at 300C. But drying yogurt storage at 400C couldn’t reformed to be good character yogurt as good as storage at 400C only 4 week storage too. After 1 month, it couldn’t bring back the yogurt form. So if it is inevitable to keep yogurt powder at a temperature of 40°C, yoghurt is maintained only up to 4 weeks.
Abstract: Potential synthesis of a series of 3-amino-4-arylazothiophene derivatives from reaction of 2-cyano-2-phenylthiocarbamoyl acetamide and the appropriate α-halogenated reagents, followed by coupling with different aryl diazonium salts (Japp-Klingemann reaction), and another series of 5-arylazo-thiazol-2-ylcarbamoyl-thiophene derivatives from base-catalyzed intramolecular condensation of 5-arylazo-2-(N-chloroacetyl)amino-thiazole with selected b-keto compounds (Thorpe-Ziegler reaction) was performed. The biological activity of the two series was studied in vitro. Their versatility for pharmaceutical purposes was reported, where they displayed remarkable activities against selected pathogenic microorganisms; Bacillus subtilis, Staphylococcus aureus (Gram positive bacteria), Escherichia coli, Pseudomonas aeruginosa (Gram negative bacteria), and Aspergillus flavus, Candida albicans (fungi) with various degrees related to their chemical structures.
Abstract: The goal of presented work is the development phytoremediation method targeted to cleaning environment polluted with organochlorine pesticides, based on joint application of plants and microorganisms. For this aim the selection of plants and microorganisms with corresponding capabilities towards three organochlorine pesticides (Lindane, DDT and PCP) has been carried out.
The tolerance of plants to tested pesticides and induction degree of plant detoxification enzymes by these compounds have been used as main criteria for estimating the applicability of plants in proposed technology. Obtained results show that alfalfa, maize and soybean among tested six plant species have highest tolerance to pesticides.
As a result of screening, more than 30 strains from genera Pseudomonas have been selected. As a result of GC analysis of incubation area, 11 active cultures for investigated pesticides are carefully chosen.
Abstract: Due to a high ethanol demand, the approach for effective ethanol production is important and has been developed rapidly worldwide. Several agricultural wastes are highly abundant in celluloses and the effective cellulase enzymes do exist widely among microorganisms. Accordingly, the cellulose degradation using microbial cellulase to produce a low-cost substrate for ethanol production has attracted more attention. In this study, the cellulase producing bacterial strain has been isolated from rich straw and identified by 16S rDNA sequence analysis as Acinetobacter sp. KKU44. This strain is able to grow and exhibit the cellulase activity. The optimal temperature for its growth and cellulase production is 37°C. The optimal temperature of bacterial cellulase activity is 60°C. The cellulase enzyme from Acinetobacter sp. KKU44 is heat-tolerant enzyme. The bacterial culture of 36h. showed highest cellulase activity at 120U/mL when grown in LB medium containing 2% (w/v). The capability of Acinetobacter sp. KKU44 to grow in cellulosic agricultural wastes as a sole carbon source and exhibiting the high cellulase activity at high temperature suggested that this strain could be potentially developed further as a cellulose degrading strain for a production of low-cost substrate used in ethanol production.
Abstract: This article comprises detail information about L-asparaginase, encompassing topic such as various sources of L-asparaginase, mechanism and properties of L-asparaginase. Also describe the production, cultivation and purification of L-asparaginase along with information about the application of L-asparaginase. L-asparaginase catalyzes the conversion reaction to convert asparagine to aspartic acid and ammonia. Asparagine is a nutritional requirement for both normal and tumor cell. Present scenario has found that L-asparaginase has been found to be a best anti tumor or antileukemic agent. In the recent years this enzyme gained application in the field of clinical research pharmacologic and food industry. It has been characterized based on the enzyme assay principle hydrolyzing L-asparagine into L-aspartic acid and ammonia. It has been observed that eukaryotic microorganisms such as yeast and filamentous fungi have a potential for L-asparaginase production. L-asparaginase has been and is still one of the most lengthily studied therapeutic enzymes by scientist and researchers worldwide.
Abstract: Sustaining a desired rate of oxygen transfer for microbial activity is a matter of major concern for biological wastewater treatment (MBR). The study reported in the paper was aimed at assessing the effects of microbial products on the specific oxygen uptake rate (SOUR) in a conventional membrane bioreactor (CMBR) and that in a sponge submerged MBR (SSMBR). The production and progressive accumulation of soluble microbial products (SMP) and bound-extracellular polymeric substances (bEPS) were affecting the SOUR of the microorganisms which varied at different stages of operation of the MBR systems depending on the variable concentrations of the SMP/bEPS. The effect of bEPS on the SOUR was stronger in the SSMBR compared to that of the SMP, while relative high concentrations of SMP had adverse effects on the SOUR of the CMBR system. Of the different mathematical correlations analyzed in the study, logarithmic mathematical correlations could be established between SOUR and bEPS in SSMBR, and similar correlations could also be found between SOUR and SMP concentrations in the CMBR.
Abstract: Environmental pollution is a global problem and best possible solution is identifying and utilizing native microorganisms. One possible application of microbial product -biosurfactant is in bioremediation of hydrocarbon contaminated sites. We have screened forty two different petroleum contaminated sites from Oman, for biosurfactant producing spore-forming bacterial isolates. Initial screening showed that out of 42 soil samples, three showed reduction in surface tension (ST) and interfacial tension (IFT) within 24h of incubation at 40°C. Out of those 3 soil samples, one was further selected for isolation of bacteria and 14 different bacteria were isolated in pure form. Of those 14 spore-forming, rod shaped bacteria, two showed highest reduction in ST and IFT in the range of 70mN/m to
Abstract: Humans use plants for thousands of years to treat various ailments, in many developing countries; much of the population relies on traditional doctors and their collections of medicinal plants to cure them.
Essential oils have many therapeutic properties. In herbal medicine, they are used for their antiseptic properties against infectious diseases of fungal origin, against dermatophytes, those of bacterial origin.
The aim of our study is to determine the antimicrobial effect of essential oils of the plant Schinus molle on some pathogenic bacteria. It is a medicinal plant used in traditional therapy. Essential oils have many therapeutic properties. In herbal medicine, they are used for their antiseptic properties against infectious diseases of fungal origin, against dermatophytes, those of bacterial origin.
The test adopted, is based on the diffusion method on solid medium (Antibiogram), this method allows to determine the susceptibility or resistance of an organism according to the sample studied.
Our study reveals that the essential oil of the plant Schinus molle has a different effect on the resistance of germs: for Pseudomonas aeruginosa strain is a moderately sensitive with an inhibition zone of 10mm, further Enterobacter, Escherichia coli and Proteus are strains that represent a high sensitivity, a zone of inhibition equal to 14.66 mm.
Abstract: The efficiency of heavy metals removal from sewage
sludge in bioleaching processes with heterotrophic, chemoautotrophic
(sulphur-oxidizing) sludge cenoses and chemical leaching (in
distilled water, weakly acidic or alkaline medium) was compared.
The efficacy of heavy metals removal from sewage sludge varies
from 83 % (Zn) up to 14 % (Cr) and follows the order: Zn > Mn > Cu
> Ni > Co > Pb > Cr. The advantages of metals bioleaching process
at heterotrophic metabolism were shown. A new process for
bioconversation of sewage sludge into fertilizer at middle
temperatures after partial heavy metals removal was developed. This
process is based on enhancing vital ability of heterotrophic
microorganisms by adding easily metabolized nutrients and synthesis
of metabolites by growing sludge cenoses. These metabolites possess
the properties of heavy metals extractants and flocculants which
provide the enhancement of sludge flocks sedimentation. The process
results in biomineral fertilizer of prolonged action with immobilized
sludge bioelements. The fertilizer satisfies the EU limits for the
sewage sludge of agricultural utilization. High efficiency of the
biomineral fertilizer obtained has been demonstrated in vegetation
experiments.