Effect of Ganoderma lucidum polysaccharides on the growth of Bifidobacterium spp. as assessed using real-time PCR

The use of component from Ganoderma lucidum as prebiotic source is interesting as the G. lucidum itself was known for more than a decade in the traditional Chinese medicine. In this work, Ganoderma lucidum crude polysaccharides (GLCP) and Polysaccharide-fraction number 2 (PF-2) were used as carbon sources in the fermentation with Bifidobacterium sp. The results showed the potential of prebiotic effect of the G. lucidum extract in batch-culture fermentation based on increment in the growth of bacteria used (0.4-1.5 log10CFU/mL) after 18h fermentation. Fermentation was further done using faecal materials as bacterial inocula and bacterial growth changes were examined using real-time PCR. The results showed the ability of GLCP and PF-2 to support the growth of Bifidobacterium genus with 0.3 and 0.7 log10cells/ml increased, respectively. Interestingly, Lactobacillus which is known as beneficial bacterial genus also showed growth increment with 0.7 and 1 log10cells/ml increased. The competition for carbon sources thus inhibits the growth of potentially harmful genus, Salmonella (0.3 and 0.5 log10cells/ml) in comparison to the control

Bacterial degradation of caffeine: a review

Caffeine (1,3,7-trimethylxanthine) is an important naturally occurring, commercially purine alkaloid which can be degraded by bacteria. It is a stimulant central nervous system and also has negative withdrawal effects and is present in different varieties of plants such as coffee plant, tea leaves, colanut, cocoa beans and other plant. It is also present in soft drinks and is being used extensively in human consumption and has in addition some therapeutic uses but in minimal amount. Evidence has proved the harmful effects of caffeine thus opening a path in the field of caffeine biodegradation. Biodegradation by bacteria is considered to be the most efficient technique in degrading caffeine within the environment. Even though there are available methods for the removal of caffeine using conventional methods such as water, supercritical and solvent decaffeination but they are lack of accuracy/specificity for the removal of caffeine and in addition to the existing caffeine which sometime remains. Microbial degradation of caffeine provides a safe and cheaper alternative compared to chemical and physical methods. Microbial candidates for caffeine biodegradation are actively being isolated globally. Caffeine degradation can occur in both aerobically and an-aerobically depending on the contaminants. Organisms such as Pseudomonas, Alcaligenes, Aspergillus, Serratia, Penicillium, Klebsiella, Stemphylium, Rhizopus, Rhodococcus, Brevibacterium, Bacillus sp., and Phanerochaete strains have been reported to have the ability to degrade caffeine

Screening of Aloe vera medium with different carbon and nitrogen sources for Lactobacillus acidophilus cultivation using fractional factorial design (FFD)

The aim of this research was to optimize the cultivation medium for economic production of a probiotic bacterium, Lactobacillus acidophilus using Aloe vera medium with different carbon (glucose, fructose and sucrose) and nitrogen (yeast extract, meat peptone, ammonium sulphate and urea) sources. Screening step was performed using 28 1/16 fractional factorial design (FFD) to investigate the significant effect of 8 factors used in this study on the biomass production expressed in log10 cfu/ mL. Biomass production was measured based on total plate count method for enumeration of viable cells. In the process of screening, the concentration range of Aloe vera, carbon and nitrogen used were from 1-2% (w/v), 1-2% (w/v) and 0.5-1% (w/v), respectively. The maximum biomass production was obtained with 11.816 log10 cfu/mL. It was shown that glucose, Aloe vera gel, combination of glucose and fructose and combination of glucose and ammonium sulphate were resulted significant (p <; 0.05) effect towards to the response, biomass production

The use of response surface methodology as a statistical tool for the optimisation of waste and pure canola oil biodegradation by Antarctic soil bacteria

Hydrocarbons can cause pollution to Antarctic terrestrial and aquatic ecosystems, both through accidental release and the discharge of waste cooking oil in grey water. Such pollutants can persist for long periods in cold environments. The native microbial community may play a role in their biodegradation. In this study, using mixed native Antarctic bacterial communities, several environmental factors influencing biodegradation of waste canola oil (WCO) and pure canola oil (PCO) were optimised using established one-factor-at-a-time (OFAT) and response surface methodology (RSM) approaches. The factors include salinity, pH, type of nitrogen and concentration, temperature, yeast extract and initial substrate concentration in OFAT and only the significant factors proceeded for the statistical optimisation through RSM. High concentration of substrate targeted for degradation activity through RSM compared to OFAT method. As for the result, all factors were significant in PBD, while only 4 factors were significant in biodegradation of PCO (pH, nitrogen concentration, yeast extract and initial substrate concentration). Using OFAT, the most effective microbial community examined was able to degrade 94.42% and 86.83% (from an initial concentration of 0.5% (v/v)) of WCO and PCO, respectively, within 7 days. Using RSM, 94.99% and 79.77% degradation of WCO and PCO was achieved in 6 days. The significant interaction for the RSM in biodegradation activity between temperature and WCO concentration in WCO media were exhibited. Meanwhile, in biodegradation of PCO the significant factors were between (1) pH and PCO concentration, (2) nitrogen concentration and yeast extract, (3) nitrogen concentration and PCO concentration. The models for the RSM were validated for both WCO and PCO media and it showed no significant difference between experimental and predicted values. The efficiency of canola oil biodegradation achieved in this study provides support for the development of practical strategies for efficient bioremediation in the Antarctic environment

Characterisation of cholinesterase from kidney tissue of Asian seabass (Lates calcarifer) and its inhibition in presence of metal ions

Aim: The chdinesterase (ChE) based inhibition studies from fish were investigated and presented here emerged to be one of thegreat potential biomarkersfor heavy metals monitoring. Methodology: In this study, the capability of ChE extracted from the kidney of Lates calcarifer was assessed for of metal. ChE was purified through ammonium sulphate precipitation and ion exchange chromatography. Results: The piffled enzyme gave 12 fold purification with the recovery of 12.17% with specific activity of 2.889 U mgJ. The Michaelis-Menten constant (K) and V,^ value obtained was 0.1426 mM and 0.0217 pmol irin'mg∗1, respectively. The enzyme has the ability to hydrolyse acetytthiocholine iodde (ATC) at a faster rate compared to other two synthetic su bstra tes , propionylthiocholine iodide (PTC) and butyrylthiocholine iodide (BTC). ChE gave highest activity at 20- 30°C in Tris-HO buffer pH 8.0. The results showed that cholinesterase from L. calcarifer kidney was very sensitive to sensitive to copper and lead after being tested argentum, arsenic, cadmium, chromium, copper, cobalt, mercury, nickel, lead and zinc. Interpretation: The effect of heavy metals studied on the activity of ChE differed from each other. The result of the study can be used as a tool for futher developing a biomarker for the detection of heavy metals in aquatic ecosystems. In addition, the information can also be used for designing a kit, that would give a rapid and accurate result

Phenol and phenolic compounds toxicity

The present of phenol and phenolic compound pollutant are the common problems faced by worldwide population due to natural and chemical process that comes from either industrial or human activity. Exceeding the standard level in our environment was not a new issue nowadays especially in developed or developing countries. The study concerning to the phenolic compound was started in the early 1908 where researchers started to look for solution and are interested in phenol-related research due to its toxicity and ability to retain in environment for a long period. Higher level of phenol leakage within the environment can actually affects the whole ecosystem. A toxicological property of phenol has been contributed by the formation of organic and free radical species and also due to its hydrophobicity. The structure of phenol itself shows its reactivity which lead to its properties like persistence in environment, toxicity and the possibilities of carcinogenic properties toward living organism

Optimisation of biodegradation conditions for cyanide removal by Serratia marcescens strain AQ07 using one-factor-at-a-time technique and response surface methodology

Gold mining companies are known to use cyanide to extract gold from minerals. The indiscriminate use of cyanide presents a major environmental issue. Serratia marcescens strain AQ07 was found to have cyanide-degrading ability. Optimisation of biodegradation condition was carried out utilising one factor at a time and response surface methodology. Cyanide degradation corresponded with growth rate with a maximum growth rate of 16.14 log cfu/mL on day 3 of incubation. Glucose and yeast extract are suitable carbon and nitrogen sources. Six parameters including carbon and nitrogen sources, pH, temperature, inoculum size and cyanide concentration were optimised. In line with the central composite design of response surface methodology, cyanide degradation was optimum at glucose concentration 5.5 g/L, yeast extract 0.55 g/L, pH 6, temperature 32.5 °C, inoculum size 20 % and cyanide concentration 200 mg/L. It was able to stand cyanide toxicity of up to 700 mg/L, which makes it an important candidate for bioremediation of cyanide. The bacterium was observed to degrade 95.6 % of 200 mg/L KCN under the optimised condition. Bacteria are reported to degrade cyanide into ammonia, formamide or formate and carbon dioxide, which are less toxic by-products. These bacteria illustrate good cyanide degradation potential that can be harnessed in cyanide remediation

Evaluation of conventional and response surface level optimisation of n-dodecane (n-C12) mineralisation by psychrotolerant strains isolated from pristine soil at Southern Victoria Island, Antarctica

Abstract Background Biodegradation of hydrocarbons in Antarctic soil has been reported to be achieved through the utilisation of indigenous cold-adapted microorganisms. Although numerous bacteria isolated from hydrocarbon-contaminated sites in Antarctica were able to demonstrate promising outcomes in utilising hydrocarbon components as their energy source, reports on the utilisation of hydrocarbons by strains isolated from pristine Antarctic soil are scarce. In the present work, two psychrotolerant strains isolated from Antarctic pristine soil with the competency to utilise diesel fuel as the sole carbon source were identified and optimised through conventional and response surface method. Results Two potent hydrocarbon-degraders (ADL15 and ADL36) were identified via partial 16S rRNA gene sequence analysis, and revealed to be closely related to the genus Pseudomonas and Rhodococcus sp., respectively. Factors affecting diesel degradation such as temperature, hydrocarbon concentration, pH and salt tolerance were studied. Although strain ADL36 was able to withstand a higher concentration of diesel than strain ADL15, both strains showed similar optimal condition for the cell’s growth at pH 7.0 and 1.0% (w/v) NaCl at the conventional ‘one-factor-at-a-time’ level. Both strains were observed to be psychrotrophs with optimal temperatures of 20 °C. Qualitative and quantitative analysis were performed with a gas chromatograph equipped with a flame ionisation detector to measure the reduction of n-alkane components in diesel. In the pre-screening medium, strain ADL36 showed 83.75% of n-dodecane mineralisation while the reduction of n-dodecane by strain ADL15 was merely at 22.39%. The optimised condition for n-dodecane mineralisation predicted through response surface methodology enhanced the reduction of n-dodecane to 99.89 and 38.32% for strain ADL36 and strain ADL15, respectively. Conclusions Strain ADL36 proves to be a better candidate for bioaugmentation operations on sites contaminated with aliphatic hydrocarbons especially in the Antarctic and other cold regions. The results obtained throughout strongly supports the use of RSM for medium optimisation

The acute toxicity of the metaldehyde on the climbing perch

In Asia, Climbing perch (Anabas testudineus) is commonly found in paddy fields and irrigation systems. Due to its habitat, Climbing perch is exposed to toxic pesticides used in paddy fields such as metaldehyde which is one of the most widely used molluscicide. This study aims to determine the acute toxicity Lethal Concentration50 (LC50) of metaldehyde and its effect on the behaviour and physical changes of the Climbing perch. The fish mortality responses to six different metaldehyde concentrations ranging from 180 to 330 mg/L were investigated. The 96-h LC50 values were determined and analysed using three different analysis methods which is arithmetic, logarithmic and probit graphic. The LC50 values obtained in this study were 239, 234 and 232 mg/L, respectively. After 96-h of exposure to metaldehyde, the fish showed a series of abnormal behavioural response in all cases: imbalance position, and restlessness of movement. The LC50 values show that metaldehyde is moderately toxic to the Climbing perch indicating that metaldehyde is not destructive to Climbing perch. However, long term exposure of aquatic organisms to the metaldehyde means a continuous health risk for the fish population as they are more vulnerable and it is on high risk for human to consume this toxicated fishes

The acute toxicity of the metaldehyde on the climbing perch

In Asia, Climbing perch (Anabas testudineus) is commonly found in paddy fields and irrigation systems. Due to its habitat, Climbing perch is exposed to toxic pesticides used in paddy fields such as metaldehyde which is one of the most widely used molluscicide. This study aims to determine the acute toxicity Lethal Concentration50 (LC50) of metaldehyde and its effect on the behaviour and physical changes of the Climbing perch. The fish mortality responses to six different metaldehyde concentrations ranging from 180 to 330 mg/L were investigated. The 96-h LC50 values were determined and analysed using three different analysis methods which is arithmetic, logarithmic and probit graphic. The LC50 values obtained in this study were 239, 234 and 232 mg/L, respectively. After 96-h of exposure to metaldehyde, the fish showed a series of abnormal behavioural response in all cases: imbalance position, and restlessness of movement. The LC50 values show that metaldehyde is moderately toxic to the Climbing perch indicating that metaldehyde is not destructive to Climbing perch. However, long term exposure of aquatic organisms to the metaldehyde means a continuous health risk for the fish population as they are more vulnerable and it is on high risk for human to consume this toxicated fishes