Nipa (Nypa fruticans) is one of the most widely distributed and useful palm in the mangrove forests in the South, Southeast Asia and Oceania. Its distribution area is known to be larger in ancient time than at present, as evidenced by its fossils found in North America, South America, Egypt and Europe. Nipa has a wide diversity of use. Traditionally it is used as roof materials, cigarette wrapper, medicine and its sap is fermented to alcohol. Recently, research on nipa has focused on its potential use as a biofuel crop because it has several advantages compared with other biofuel-alcohol crops. For example it has high alcohol content, no competition with other crop for agricultural land and no bagasse disposal problem. In spite of such usefulness, scientific reports on biology of nipa are limited. Information on genetic diversity, cytogenetics and chemical composition are lacking for nipa plant. On the other hand, morphological characters of nipa have been described in many reports. This paper attempted to provide a general review of the nipa plant based on available literatures.
Polyhydroxybutyrate (PHB) otherwise known as bioplastics are biodegradable materials that are accumulated in various microorganisms to serve as carbon and energy reservoirs and regarded as an attractive alternative to petroleum-derived plastics. Although research has been conducted on isolation of PHB-producing microorganisms from different ecological environments, few studies have been carried out on isolation of potential PHB-producing microorganisms from rhizosphere environment of groundnut plants, Arachis hypogaea which can be regarded as a good environment for the isolation of potential PHB-producing microorganisms. In the present study, a total of twenty-one (21) bacterial strains were primarily screened and isolated from rhizosphere soil of a groundnut plant. Four bacterial isolates with maximum PHB-producing potential upon screening using submerged fermentation were selected for further studies. The fermentation pattern of PHB production was studied using different nutrient sources. The influence of agitation on PHB production was also studied. Mannitol stimulated maximum (6.076a mg/mL) PHB production by Bacillus sp. 1; KNO3 used as a limiting nutrient induced best (5.728a mg/mL) PHB production by Citrobacter sp. and MgSO4.7H2O supported maximum (5.972a mg/mL) PHB production in Enterococcus sp. A low agitation speed of 150 rpm was found to support best (5.802a mg/mL) PHB production by Bacillus sp.1. Findings from this study indicated that the isolated bacterial strains have high PHB- producing potential. The need to explore other environment harbouring microbial strains with high PHB-producing potential is paramount to the discovery of bioplastics with improved properties for potential industrial applications.
Fungi associated with Vaccinium species play important roles in plant growth and disease control, especially in the final
blueberry production. Vaccinium dunalianum var. urophyllum (Ericaceae) is a well-known medicinal plant in Southern
China used to treat inflammation and microbial infections. The endophytic fungi from these plants are therefore anticipated
as potential new sources of antimicrobials. In this report, the inhibitory effects of endophytes against clinical bacteria
and yeast were comprehensively screened and 11 isolates indicated high bioactivity by the agar diffusion method. The
corresponding crude extracts of these fungi under submerged fermentation also demonstrated distinct differences and
n-butyl alcohol displayed the lowest extraction efficiency among the extracts. The ethyl acetate and dichloromethane
extracts of filtrates from the Colletotrichum sp. VD001, Epicoccum nigrum VD021 and E. nigrum VD022 strains
displayed good properties against pathogenic microorganisms according to disc diffusion assays and minimal inhibitory
concentration (MIC). This study is the first indicating that cultivable endophytic fungi associated with blueberry plants
produce potential compounds against clinical pathogens.
Algae have recently received a lot of attention as a new biomass source for the production of renewable energy and an important bioremediation agent. This study was carried out to evaluate the potential of green algae Scenedesmus obliquus grow in different concentrations of wastewater and the improvement of cultivation conditions to produce biomass rich in sugar to produce bioethanol by fermentation processes. The highest sugar content of S. obliquus biomass was recorded for algae cultivated with 40 and 85% wastewater after 9 days under aeration condition with dark and light duration (44.5%). It was found that the highest removal efficiency of BOD and COD were 18% for S. obliquus grown under aeration condition. The highest ethanol efficiency of S. obliquus biomass hydrolysate was 20.33% at 4th day. The best condition of S. obliquus to grow efficiently was under aeration with light and dark durations, where it has high efficiency to remove heavy metals from wastewater in this condition.
Sweatings, the exudates that leach out from fermenting fruits during rambutan fruit fermentation are considered as
a waste by-product and are allowed to be drained off. This could lead to a pollution problem. Besides, it is a waste if
the sweatings are possible to be transformed into food products and ingredients. However, prior transformation, the
fundamental knowledge of the sweatings should be understood. Hence, the main aim of this study was to investigate
the physicochemical properties of sweatings as affected by fermentation time and turning intervals during natural
fermentation of rambutan fruits. In this study, peeled rambutan fruit was fermented for 8 days and turned. Different
batches of the fruits were turned every 24, 48 or 72 h and sweatings from the process were collected and analyzed.
The results showed that fermentation time significantly reduced (p<0.05) the yield, pH and sucrose content of the
sweatings by 79-84%, 32-33%, 76.5-80.8%, respectively. Fermentation time also significantly increased (p<0.05) the
titratable acidity, total soluble solids, fructose, glucose, total sugar, citric acid, lactic acid, acetic acid and ascorbic
acid contents of the sweatings by 5.6-6.0, 1.5-1.6, 2.4-2.6, 2.1-2.5, 1.0-1.1, 5.7-6.5, 2.4-2.6, 2.1-2.5 and 2.6-2.8 folds,
respectively. However, turning intervals did not significantly affect (p>0.05) the physicochemical properties of the
sweatings. High concentrations of sugars and organic acids allow the sweatings to have a balance of sweet and sour
taste and they are suitable to be used in the production of syrup, soft drinks, jam, jelly, marmalade and vinegar.
FERMSOSTAT is a developed laboratory scale solid state fermenter. It is a horizontal stirrer drum bioreactor with about 70 L capacities. The fermenter is made of stainless steel which is anti-corrosive and non-toxic to the process organism. The fermenter is equipped with sets of control systems for temperature, agitation, aeration and also outlets for substrate sampling as well as inlets for inoculation and substrate additions. The uniqueness of this FERMSOSTAT system is its ability to carry out in situ substrate sterilization and extraction of enzymes at the end of SSF process. Moreover, the mixing system provided by FERMSOSTAT can be performed either full or half mixing as well as forward or reverse mixing. Furthermore, the mixing can be programmed to run at certain agitation rate and time interval during the fermentation process to prevent or reduce damage to the fungus mycelia. FERMSOSTAT is a developed SSF bioreactor and not an improvement of any existing one. The performances of FERMSOSTAT have been evaluated. Under optimum solid state fermentation conditions, about 63.4, 397 and 3.21 U/g of CMCase, xylanase and FPase activities were detected, which were higher compared to the tray system.
Response surface methodology (RSM) with central composite design (CCD) was applied to optimize key factors affecting
hydrogen production (HP) from diluted acid hydrolysate of water-hyacinth stem (WHS) by heat-treated anaerobic sludge
in a batch fermentation process. Key factors affecting namely substrate concentration and initial pH was investigated.
The results indicated that substrate concentration and initial pH had significantly effects on HP (p<0.05). A maximum HP
hydrogen production rate and hydrogen yield of 182.7 mmol H2
/L, 2.81 mmol H2
/L h and 0.84 mol H2
/mol hexose were
obtained under the optimum conditions i.e. substrate concentration of 4.06 g/L and initial pH of 5.81. The total energy
production from the fermentative of WHS hydrolysate was 1.97 kJ.
Phytase activity and growth of anaerobic rumen bacterium, Mitsuokella jalaludinii were investigated by semi-solid
state fermentation. Carbon source (rice bran, yam and cassava), nitrogen sources (soya bean, offal meal, fish meal and
feather meal) and growth factors (hemin, L-cysteine hydrochloride and minerals) were evaluated in a one-factor-at-atime
approach. Rice bran and fish meal produced better growth and phytase enzyme activity. The removal of L-cysteine
hydrochloride and minerals significantly decreased (p<0.05) phytase activity from 1178.72 U to 446.99 U and 902.54
U, respectively. The response surface methods (RSM) was conducted to optimize the phytase production and the results
showed the combination of 7.7% of rice bran and 3.7% of fish meal in semi-solid state fermentation gave the highest
phytase activity. Maximum phytase production and optimum growth of bacteria were detected at 12 h incubation in both
MF medium (control) and agro-medium. In this agro-medium, M. jalaludinii produced 2.5 fold higher phytase activity
compared to MF medium.
Burkholderia cenocepacia and Serratia marcescens are Gram-negative proteobacteria commonly found in the natural
environment and are also opportunistic pathogens that caused a number of human diseases. The fermentation culture of
Burkholderia cenocepacia yielded three compounds, 4-(2-hydroxyethoxy)-phenol (1), Maculosin (2) and methyl myristate
(3). Compound 2 was also isolated together with cyclo(L-Leu-L-Pro) (4) from Serratia marcescens. Compound 1 was
isolated from a natural source for the first time and the first isolation of compounds 2-4 was also reported from both
Burkholderia cenocepacia and Serratia marcescens.
The development and utilization of clean energy has long been a focus of research. In the coal bed methane field, most coal bed biogenic methane experiments are small static sample tests in which the initial conditions are set and the process cannot be batch-fed elements and microbial strains, and the gas cannot be collected in batches. Although significant results have been achieved in the coal-to-biogenic methane conversion in China, findings are restricted to the laboratory scale. No successful commercialization of coal bed biogenic methane production has been achieved yet. This study used a large-capacity fermentation tank (5 L) to conduct biogenic methane experiments. Results were compared to those from the traditional laboratory test. The gas production rate and gas concentration were higher when the 250 mL methane test volume was increased to a 5 L fermentation volume, increasing by 20.9% and 2.3%, respectively. The inhibition effect of the liquid phase products was reduced in the large fermentation tank, and the microbial activity was extended by batch feeding trace elements (iron and nickel) and methane strains and by semi-continuous collection of the gas. However, the gas conversion rate can be increased by retaining the H2 and CO2 in the intermediate gas products in the fermentation tank. The gas production rate was increased from 17.9 to 24.6 mL/g, increasing by 37.4%. The simulation pilot test can lay a foundation for the transition from a coal bed biogenic methane laboratory static small sample test to a dynamic pilot test, optimizing the process parameters to improve the reaction efficiency and move forward to commercialization test.
Fermented Virgin Coconut Oil (FVCO) is widely used in the Southeast Asia as food and traditional medicine. The objective of the present study is the evaluation of chronic safety of the commercialized FVCO of Malaysia and other Southeast Asian countries. A single dose of 5000 mg/kg of FVCO was administered orally in rats (each group, n = 5) for the acute toxicity study and 175, 550 and 2000 mg/kg for sub-chronic and chronic studies (each group, n = 10), respectively. The behavior, mortality, and body weight of the rats were assessed to determine the toxic effects of FVCO. The haematology, biochemistry and histopathology of the treated rats were evaluated. The treated rats were safe with the dose of 5000 mg/kg in acute, sub-chronic and chronic indication. Abnormal clinical signs and morphology (gross necroscopy), changes of organ weight, anomalous haematology and biochemistry indexes were not found in comparison with the control (p > 0.05). In general, food and water intake were higher in the treated rats related to control. It was concluded that the presence of the antioxidant active compounds of FVCO might be the reason of safety. The structure activity relationship (SAR) provides a comprehensive mechanism to determine the safety that is the presence of the electron donating phenolic groups, carbonyl groups, and carboxylic acid in the ortho and meta position of the aromatic rings. The SAR showed the antioxidant properties of myristic acid and lauric acid determined by GC-MS analysis. This result suggests the safety of FVCO for chronic use, nutritional activity that FVCO formulation complies the requirements of regulatory agencies.
Milk kefir fermentation has been used in households for generations. Consumption of milk kefir has been associated with various health benefits, presumably from the probiotics of yeast and bacteria that make up the kefir grains. In addition, many of the microbes are known to produce novel antimicrobial compounds that can be used for other applications. The microbes living inside kefir grains differ significantly depending on geographical location and production methods. In this study, we aimed to use metagenomic analysis of fermented milk by using three different kefir grains (kefir 1, kefir 2, and kefir 3) from different US sources. We analyzed the microbial compositions of the three milk fermentation samples. This study revealed that each sample contains unique and distinct groups of microbes, kefir 1 showed the least diversity, and kefir 3 showed the highest diversity. Kefir 3 is rich in Proteobacteria while kefir 2 is dominated by the Firmicutes. Using bacterial indicator growth analyses carried out by continuous readings from microplate-based bioreactor assays suggested that kefir 2 fermentation filtrate has higher antibacterial property. We have screened 30 purified cultures of kefir 2 sample and isolated two lactic acid bacteria strains with higher antibacterial activities; the two strains were identified as Leuconostoc mesenteroides 28-1 and Lentilactobacillus kefiri 25-2 by 16S genomic PCR with confirmed antibacterial activities of fermentation filtrate after growing under both aerobic and anaerobic conditions.
The culture conditions for gibberellic acid (GA3) production by the fungus Penicillium variable (P. variable) was optimized using a statistical tool, response surface methodology (RSM). Interactions of culture conditions and optimization of the system were studied using Box-Behnken design (BBD) with three levels of three variables in a batch flask reactor. Experimentation showed that the model developed based on RSM and BBD had predicted GA3 production with R(2) = 0.987. The predicted GA3 production was optimum (31.57 mg GA3/kg substrate) when the culture conditions were at 7 days of incubation period, 21% v/w of inoculum size, and 2% v/w of olive oil concentration as a natural precursor. The results indicated that RSM and BBD methods were effective for optimizing the culture conditions of GA3 production by P. variable mycelia.
An optimized cultivation condition is needed to maximize the functional green fluorescent protein (GFP) production. Six process variables (agitation rate, temperature, initial medium pH, concentration of inducer, time of induction, and inoculum density) were screened using the fractional factorial design. Three variables (agitation rate, temperature, and time of induction) exerted significant effects on functional GFP production in E. coli shake flask cultivation and were optimized subsequently using the Box-Behnken design. An agitation rate of 206 rpm at 31°C and induction of the protein expression when the cell density (OD(600nm)) reaches 1.04 could enhance the yield of functional GFP production from 0.025 g/L to 0.241 g/L, which is about ninefold higher than the unoptimized conditions. Unoptimized cultivation conditions resulted in protein aggregation and hence reduced the quantity of functional GFP. The model and regression equation based on the shake flask cultivation could be applied to a 2-L bioreactor for maximum functional GFP production.
The response surface method was applied in this study to improve cellulase production from oil palm empty fruit bunch (OPEFB) by Botryosphaeria rhodina. An experimental design based on a two-level factorial was employed to screen the significant environmental factors for cellulase production. The locally isolated fungus Botryosphaeria rhodina was cultivated on OPEFB under solid-state fermentation (SSF). From the analysis of variance (ANOVA), the initial moisture content, amount of substrate, and initial pH of nutrient supplied in the SSF system significantly influenced cellulase production. Then the optimization of the variables was done using the response surface method according to central composite design (CCD). Botryosphaeria rhodina exhibited its best performance with a high predicted value of FPase enzyme production (17.95 U/g) when the initial moisture content was at 24.32%, initial pH of nutrient was 5.96, and 3.98 g of substrate was present. The statistical optimization from actual experiment resulted in a significant increment of FPase production from 3.26 to 17.91 U/g (5.49-fold). High cellulase production at low moisture content is a very rare condition for fungi cultured in solid-state fermentation.
Enzymatic production of bioxylitol from lignocellulosic biomass (LCB) provides a promising alternative to both chemical and fermentative routes. This study aimed to assess the impacts of catalytic variables on bioxylitol production from wood sawdust using xylose reductase (XR) enzyme and to optimize the bioprocess. Enzyme-based xylitol production was carried out in batch cultivation under various experimental conditions to obtain maximum xylitol yield and productivity. The response surface methodology (RSM) was followed to fine-tune the most significant variables such as reaction time, temperature, and pH, which influence the synthesis of bioxylitol from sawdust hydrolysate and to optimize them. The optimum time, temperature, and pH became were 12.25 h, 35 °C, and 6.5, respectively, with initial xylose 18.8 g/L, NADPH 2.83 g/L, XR 0.027 U/mg, and agitation 100 rpm. The maximum xylitol production was attained at 16.28 g/L with a yield and productivity of 86.6% (w/w) and 1.33 g/L·h, respectively. Optimization of catalytic parameters using sequential strategies resulted in 1.55-fold improvement in overall xylitol production. This study explores a novel strategy for using sawdust hemicellulose in bioxylitol production by enzyme technology.
In this work, porous glass beads grafted with polyethylene glycol (PEG) were used as an adsorbent to purify lipase from Burkholderia metallica in column chromatography. The purification parameters viz. salt stability, types and concentrations of PEG and salt, pH of the binding solution, and flow rate were studied to determine the performance of the purification system in an XK16/20 column. The crude lipase was mixed with different types and concentrations of salts 1-5% (w/w) (sodium citrate, potassium citrate, and sodium acetate) and subjected to the column containing the polymeric glass bead. One-variable-at-a-time experimentation revealed that 20% (w/w) PEG 6000 g/mol impregnated glass beads with a binding solution of 5% sodium citrate at pH 7.7, a flow rate of 1.0 mL/min and extraction time of 10 min resulted in the highest purification factor and recovery yield at 3.67 and 88%, respectively. The purified lipase has 55 ∼ 60 kDa molecular mass. The outcome of the study showed PEG could be applied to modify the inert glass beads into polymeric form, providing a biocompatible and mild separation condition for lipase. Thus, PEG could be successfully applied for the purification of lipase from B. metallica fermentation broth using column chromatography.
Lower temperature biohydrogen production has always been attractive, due to the lower energy requirements. However, the slow metabolic rate of psychrotolerant biohydrogen-producing bacteria is a common problem that affects their biohydrogen yield. This study reports on the improved substrate synthesis and biohydrogen productivity by the psychrotolerant Klebsiella sp. strain ABZ11, isolated from Antarctic seawater sample. The isolate was screened for biohydrogen production at 30°C, under facultative anaerobic condition. The isolate is able to ferment glucose, fructose and sucrose with biohydrogen production rate and yield of 0.8 mol/l/h and 3.8 mol/g, respectively at 10 g/l glucose concentration. It also showed 74% carbohydrate uptake and 95% oxygen uptake ability, and a wide growth temperature range with optimum at 37°C. Klebsiella sp. ABZ11 has a short biohydrogen production lag phase, fast substrate uptake and is able to tolerate the presence of oxygen in the culture medium. Thus, the isolate has a potential to be used for lower temperature biohydrogen production process.
Previous studies on the nutritional and nutraceutical properties of Lignosus rhinocerotis focused mainly on the sclerotium; however, the supply of wild sclerotium is limited. In this investigation, the antioxidant capacity and cytotoxic effect of L. rhinocerotis cultured under different conditions of liquid fermentation (shaken and static) were compared to the sclerotium produced by solid-substrate fermentation. Aqueous methanol extracts of the mycelium (LR-MH, LR-MT) and culture broth (LR-BH, LR-BT) demonstrated either higher or comparable antioxidant capacities to the sclerotium extract (LR-SC) based on their radical scavenging abilities, reducing properties, metal chelating activities, and inhibitory effects on lipid peroxidation. All extracts exerted low cytotoxicity (IC50>200 µg/ml, 72 h) against selected mammalian cell lines. Several low-molecular-weight compounds, including sugars, fatty acids, methyl esters, sterols, amides, amino acids, phenolics, and triterpenoids, were identified using GC-MS and UHPLC-ESI-MS/MS. The presence of proteins (<40 kDa) in the extracts was confirmed by SDS-PAGE and SELDI-TOF-MS. Principal component analysis revealed that the chemical profiles of the mycelial extracts under shaken and static conditions were distinct from those of the sclerotium. Results from bioactivity evaluation and chemical profiling showed that L. rhinocerotis from liquid fermentation merits consideration as an alternative source of functional ingredients and potential substitute for the sclerotium.
The fermentation of cocoa pulp is one of the few remaining large-scale spontaneous microbial processes in today's food industry. The microbiota involved in cocoa pulp fermentations is complex and variable, which leads to inconsistent production efficiency and cocoa quality. Despite intensive research in the field, a detailed and comprehensive analysis of the microbiota is still lacking, especially for the expanding Asian production region. Here, we report a large-scale, comprehensive analysis of four spontaneous Malaysian cocoa pulp fermentations across two time points in the harvest season and two fermentation methods. Our results show that the cocoa microbiota consists of a "core" and a "variable" part. The bacterial populations show a remarkable consistency, with only two dominant species, Lactobacillus fermentum and Acetobacter pasteurianus. The fungal diversity is much larger, with four dominant species occurring in all fermentations ("core" yeasts), and a large number of yeasts that only occur in lower numbers and specific fermentations ("variable" yeasts). Despite this diversity, a clear pattern emerges, with early dominance of apiculate yeasts and late dominance of Saccharomyces cerevisiae. Our results provide new insights into the microbial diversity in Malaysian cocoa pulp fermentations and pave the way for the selection of starter cultures to increase efficiency and consistency.