Reduction of hydrogen sulphide in chicken manure by immobilized sulphur oxidising bacteria isolated from hot spring

The rapid development of the poultry industry has led to the production of large amounts of manure, which produce substances like hydrogen sulfide (H2S) that contribute to odor pollution. H2S is a highly undesirable gas component and its removal from the environment is therefore necessary. Sulfur-oxidizing bacteria (SOB) are widely known to remove contaminating H2S due to their ability to oxidize reduced sulfur compounds. In this study, three potential SOB (designated AH18, AH25, and AH28) that were previously isolated from a hot spring in Malaysia were identified by 16S rRNA gene analysis. Laboratory-scale biological deodorization experiments were conducted to test the performance of the three isolates—in the form of pure or mixed cultures, with the cells immobilized onto alginate as a carrier—in reducing the H2S from chicken manure. On the basis of 16S rRNA phylogenetic analysis, isolate AH18 was identified as Pseudomonas sp., whereas isolates AH25 and AH28 were identified as Achromobacter sp. The most active deodorizing isolate was AH18, with an H2S reduction rate of 74.7% (p 0.05), respectively. However, the H2S removal performance was enhanced in the mixed culture, with a reduction rate of 81.9% (p < 0.05). In conclusion, the three potential SOB isolates were capable of reducing the H2S from chicken manure in the form of a pure culture immobilized on alginate, and the reduction performance was enhanced in the mixed culture

Modelling of Swarm Communication

Swarm communication is a communication process of sending data within a certain area via agents.. Data will be sent to all the agents in this process. This is also closely related to the way of broadcasting via “short communication” as a way to find out the data among their agents. This field involved an in -depth study of the behaviour of the agents and by using a homogeneous approach, inspect the process of sending data. This includes investigation of independence of agents and the characteristics of sending and receiving data for a random process in a swarm. In this paper, techniques useful for swarm implemented bit-communication behaviour will be presented. There are two approaches that are used to send and receive signals. The reverse approach is where data can be resend to the sender for the next cycle, where the program randomly selects the nearest agents t o send data to. While for the nonreversing approach data is not able to return to the sender in the previous cycle. The non -reversing approach can improve system performance and efficiency. This paper presents the development of a swarm communication mode l and how it can be used to illustrate the communication process

Optimization of protective agents for the freeze-drying of Paenibacillus polymyxa Kp10 as a potential biofungicide

Anthracnose is a fungal disease causing major losses in crop production. Chemical fungicides widely used in crop plantations to combat fungal infections can be a threat to the environment and humans in the long term. Recently, biofungicides have gained much interest as an alternative to chemical fungicides due to their environmentally friendly nature. Biofungicide products in powder form can be formulated using the freeze-drying technique to provide convenient storage. Protective agent formulation is needed in maintaining the optimal viable cells of biofungicide products. In this study, 8.10 log colony-forming unit (CFU)/mL was the highest cell viability of Paenibacillus polymyxa Kp10 at 22 h during incubation. The effects of several selected protective agents on the viability of P. polymyxa Kp10 after freeze-drying were studied. Response surface methodology (RSM) was used for optimizing formulation for the protective agents. The combination of lactose (10% w/v), skim milk (20% w/v), and sucrose (27.5% w/v) was found to be suitable for preserving P. polymyxa Kp10 during freeze-drying. Further, P. polymyxa Kp10 demonstrated the ability to inhibit fungal pathogens, Colletotrichum truncatum and C. gloeosporioides, at 60.18% and 66.52% of inhibition of radial growth, respectively

Effect of cultural conditions on protease production by a thermophilic Geobacillus thermoglucosidacius SKF4 isolated from Sg Klah Hot Spring Park, Malaysia

Major progress in the fields of agriculture, industry, and biotechnology over the years has influenced the quest for a potent microorganism with favorable properties to be used in scientific research and industry. This study intended to isolate a new thermophilic-protease-producing bacterium and evaluate its growth and protease production under cultural conditions. Protease producing bacteria were successfully isolated from Sungai Klah Hot Spring Park in Perak, Malaysia, and coded as SKF4; they were promising protease producers. Based on microscopic, morphological, and 16S rRNA gene analysis, isolate SKF4 was identified as Geobacillus thermoglucosidasius SKF4. The process of isolating SKF4 to grow and produce proteases under different cultural conditions, including temperature, pH, NaCl concentration, carbon and nitrogen sources, and incubation time, was explored. The optimum cultural conditions observed for growth and protease production were at 60 to 65 °C of temperature, pH 7 to 8, and under 1% NaCl concentration. Further, the use of casein and yeast extract as the nitrogen sources, and sucrose and fructose as the carbon sources enhanced the growth and protease production of isolate SKF4. Meanwhile, isolate SKF4 reached maximum growth and protease production at 24 h of incubation time. The results of this study revealed a new potent strain of thermophilic bacterium isolated from Sungai Klah Hot Spring Park in Perak, Malaysia for the first time. The high production of thermostable protease enzyme by G. thermoglucosidasius SKF4 highlighted the promising properties of this bacterium for industrial and biotechnological applications

Microbial synthesis of zinc oxide nanoparticles and their potential application as an antimicrobial agent and a feed supplement in animal industry: a review

In recent years, zinc oxide nanoparticles (ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles (NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods. Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, non-toxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal’s body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals

Sedative, cognitive impairment and anxiolytic effects of acute Mitragyna speciosa in rodents

Mitragyna speciosa, a plant from Rubiaceae family, was reported to have an opium-like effect and their coca-like stimulative ability to combat fatigue and enhance tolerance to hard work. There are lack of information regarding to the effect of Mitragyna speciosa on cognitive and behavioural performances. Therefore the project was conducted to observe the effect of Mitragyna speciosa on cognitive behavior of rats and mice. Mitragyna speciosa in methanol extract form and aqueous extract form with same dosage distributions were used; 10 mg/kg, 30 mg/kg, and 100 mg/kg. Four tests were conducted to observe the behavioural changes of the animal namely locomotor, cognitive performances, anxiety and rotarod performance. Results showed that all dosage of treatment reduced locomotor and impaired cognitive performance significantly. Study showed that Mitragyna speciosa induce sedative effect in dose dependant manner. Interestingly, Mitragyna speciosa increased the time spent in open arm of plus maze indicating low anxiety level of the rodent. As conclusion, Mitragyna speciosa caused sedative effect, impairment in working memory, and possess anxiolytic properties

Antibacterial Potential of Biosynthesized Zinc Oxide Nanoparticles against Poultry-Associated Foodborne Pathogens: An In Vitro Study

Since the emergence of multidrug-resistant bacteria in the poultry industry is currently a serious threat, there is an urgent need to develop a more efficient and alternative antibacterial substance. Zinc oxide nanoparticles (ZnO NPs) have exhibited antibacterial efficacy against a wide range of microorganisms. Although the in vitro antibacterial activity of ZnO NPs has been studied, little is known about the antibacterial mechanisms of ZnO NPs against poultry-associated foodborne pathogens. In the present study, ZnO NPs were successfully synthesized using Lactobacillus plantarum TA4, characterized, and their antibacterial potential against common avian pathogens (Salmonella spp., Escherichia coli, and Staphylococcus aureus) was investigated. Confirmation of ZnO NPs by UV-Visual spectroscopy showed an absorption band center at 360 nm. Morphologically, the synthesized ZnO NPs were oval with an average particle size of 29.7 nm. Based on the dissolution study of Zn2+, ZnO NPs released more ions than their bulk counterparts. Results from the agar well diffusion assay indicated that ZnO NPs effectively inhibited the growth of the three poultry-associated foodborne pathogens. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were assessed using various concentrations of ZnO NPs, which resulted in excellent antibacterial activity as compared to their bulkier counterparts. S. aureus was more susceptible to ZnO NPs compared to the other tested bacteria. Furthermore, the ZnO NPs demonstrated substantial biofilm inhibition and eradication. The formation of reactive oxygen species (ROS) and cellular material leakage was quantified to determine the underlying antibacterial mechanisms, whereas a scanning electron microscope (SEM) was used to examine the morphological changes of tested bacteria treated with ZnO NPs. The findings suggested that ROS-induced oxidative stress caused membrane damage and bacterial cell death. Overall, the results demonstrated that ZnO NPs could be developed as an alternative antibiotic in poultry production and revealed new possibilities in combating pathogenic microorganisms

Isolation, identification and characterisation of sulphur-oxidising bacteria isolated from hot spring for reduction of hydrogen sulphide in chicken manure

The rapid development of poultry industry has led to the production of large amounts of manure which contributed to odour pollution such as hydrogen sulphide (H2S). Hydrogen sulphide is widely known as the most undesirable gas component and therefore, H2S removal from the environment is necessary. Generally, chemical and physical methods have been used for the removal of H2S, however, this method is costly and often results in secondary pollution. Recently, the biological method has drawn so much attention due to its efficiency, low-cost method, and environmentally friendly. It has been widely known that sulphur oxidising bacteria (SOB) can be used to remove contaminating H2S due to its ability to oxidise the reduced sulphur compounds. Thus, this study was conducted to isolate, characterise and identify a potential SOB from hot spring in Malaysia in reducing the H2S from chicken manure. Three potential SOB has been isolated in this work which namely as isolate AH18, AH25, and AH28. Isolate AH18 was identified as Pseudomonas sp. meanwhile isolate AH25 and AH28 was identified as Achromobacter sp. based on 16S rRNA phylogenetic analysis. The optimum pH for growth of all the isolates occurred at pH 8.0. Moreover, the optimum temperature for isolate AH18, AH25 and AH28 occurred at 45 °C, 30 °C and 30-45 °C respectively. The three isolates were classified as facultative chemolithotroph with the capability of growth at thiosulphate concentration as high as 100 mM. The pure culture and the mixed culture of the isolates were immobilised on perlite and alginate for cell immobilisation to test their H2S removal performance in chicken manure. The laboratory-scale experiments revealed that the most active isolate was AH18 with a reduction rate of 67.3% and 74.7% when carried on perlite and alginate respectively. Meanwhile, the reduction rate for isolate AH25 was 59% and 54.2% when carried on perlite and alginate respectively, and for isolate AH28 was 63.2% and 60.8% when carried on perlite and alginate respectively. However, the removal performance of H2S was enhanced in mixed culture with 69.6% and 81.9% of reduction rate carried on perlite and alginate respectively. Additionally, based on the results obtained, the reduction rate of H2S in chicken manure was observed higher when the potential SOB and the mixed culture were carried on alginate than on perlite. In conclusion, three potential SOB isolates were successfully isolated from hot spring in Malaysia with their ability in reducing the H2S from chicken manure in the form of pure culture and mixed culture. Moreover, based on the results obtained, these potential SOB isolates could be a potent candidate for biological deodorisation due to their pH, temperature adaptability, metabolic flexibility and H2S removal efficiency in chicken manure. In addition, to achieve the higher H2S removal ability, the mixed culture carried on alginate could be the best alternative for H2S deodorisation application

Optimization of biosynthesis zinc oxide nanoparticles: desirability-function based response surface methodology, physicochemical characteristics, and its antioxidant properties

The optimization of zinc oxide nanoparticles (ZnO NPs) with maximum yield and smaller particle size synthesized using cell-free supernatant (CFS) of Lactobacillus plantarum TA4 were investigated using a desirability-function based response surface methodology (RSM). A central composite rotatable design (CCRD) with five levels and three factors namely zinc concentration (200-500 mM), pH (6-10), and CFS volume ratio (20-50%) were employed to study the response variables. A total of 20 experimental runs were performed and desirability-function showed that the optimal conditions for the maximum yield and minimum particle size were 352.4 mM of Zn concentration, pH 9, and 25 % of CFS volume ratio. At these optimal conditions, the predicted yield and size of the optimized ZnO NPs were 2.47 g and 75.8 nm, respectively. The validation test showed 2.41 g of yield and an average size of 80.5 nm. The UV-Vis spectroscopy showed the characteristic surface plasmon resonance band (SPR) at an absorption peak of 360 nm, confirming the formation of optimized ZnO NPs. Dynamic light scattering (DLS) demonstrated the small hydrodynamic size and low polydispersity index (PDI) of ZnO NPs at 85.9 nm and 0.243, respectively. A high-resolution transmission electron microscope (HRTEM) analysis illustrated spherical and oval-shaped ZnO NPs with an average particle size of 29.7 nm. Furthermore, Fourier-transform infrared (FTIR) analysis showed that biological compounds (proteins, enzymes, and carbohydrates) from CFS were involved in the reduction and capping of ZnO NPs. Raman spectroscopy and thermogravimetric analysis (TGA) demonstrated the crystallinity and thermal stability of ZnO NPs. Furthermore, the total antioxidant capacity (TAC) and free radical scavenging activity (RSA) of ZnO NPs demonstrated promising antioxidant properties when compared to their bulkier counterparts. Overall, this work paves the way for a cleaner and environmentally friendly production of ZnO NPs for industrial use