The University of New South WalesBiotechnology · Doctor of PhilosophyAustralia · Sydney
The University of New South WalesBioprocess · Bachelor of EngineeringSydney
Article: Possible synergistic effect between high lactate and insufficient intake of peptides caused biomass reduction during high-cell starter culture production.M Boonmee[show abstract] [hide abstract]
ABSTRACT: Lactic starter culture production is normally subjected to the end-product inhibition on growth, which limits the biomass produced per production batch. Removal of lactate ions during the biomass production has improved the biomass production. It allows for the use of higher sugar concentration so that high biomass concentration can be obtained. Lactate removal by ion exchange resin during Lactococcus lactis NZ133 cultivation was applied as a strategy for enhancing the production of lactic starter culture biomass. At high lactose concentrations of 180 g/l, the unexpected reduction in the biomass was evident regardless of the remaining sugar in the fermentation broth. The amount of protein and proteins/polypeptides pattern profile during cultivation were investigated as protein availability was suspected to be the potential cause of biomass reduction during high cell cultivation applying the ion exchange technique. Reduction in biomass concentration, after its maximum of 26 g/l, was observed after the protein concentration was unchanged while the remaining lactose continued to be utilised. A sharp decrease in protein concentration following the addition of resin corresponded to the disappearance of the smear band of protein sized 6,512-26,625 Da when more resin was added to remove lactate. The smear band remained throughout the conventional batch cultivation period. Based on the results, insufficient supply of peptides caused by the loss through adsorption onto ion exchange resin which occurred at high lactate level was postulated as the most probable cause of the biomass reduction. The result also indicated an inefficient use of supplemented protein sources supplied in correspond to the increase in lactose concentration due to the presence of appreciable amounts of residual protein at the end of cultivation process.Beneficial microbes. 06/2010; 1(2):175-82.
Article: Hazardous Gases and Oxygen Depletion in a Wet Paddy Pile: an Experimental Study in a simulating Underground Rice Mill Pit, Thailand.[show abstract] [hide abstract]
ABSTRACT: During the rice harvesting season in Thailand, large amounts of fresh paddy are sent to rice mills immediately after harvesting due to a lack of proper farm storage space. At certain levels of moisture content, rice grains may generate hazardous gases, which can replace oxygen (O2) in the confined spaces of underground rice mill pits. This phenomenon has been observed in a fatal accident in Thailand. Our study aimed to investigate the type of gases and their air concentrations emitted from the paddy piles at different levels of moisture content and duration of piling time. Four levels of moisture content in the paddy piles were investigated, including dry paddy group (< 14% wet basis (wb)), wet paddy groups (22-24, 25-27 and 28-30 %wb). Our measurements were conducted in 16 experimental concrete pits 80 × 80 cm wide by 60 cm high. Gases emitted were measured with an infrared spectrophotometer and a multi-gas detector every 12 hr for 5 days throughout the experiment. The results revealed high levels of carbon dioxide (CO(2)) (range 5,864-8,419 ppm) in all wet paddy groups, which gradually increased over time. The concentration of carbon monoxide (CO), methane (CH(4)), nitromethane (CH(3)NO(2)) and nitrous oxide (N(2)O) in all wet paddy groups increased with piling time and with moisture content, with ranges of 11-289; 2-8; 36-374; and 4-26 ppm, respectively. The highest levels of moisture content in the paddy piles were in the range 28-30 %wb. Nitrogen dioxide (NO(2)) concentrations were low in all paddy groups. The percentage of O(2) in the wet paddy groups decreased with piling time and moisture content (from 18.7% to 4.1%). This study suggested that hazardous gases could be emitted in moist paddy piles, and their concentrations could increase with increasing moisture content and piling time period.Industrial Health 10/2012; · 0.94 Impact Factor
Article: Isolation and characterization of bacteria capable of producing pyridoxamine (PM) and pyridoxamine 5'-phosphate (PMP), vitamin B6 compounds.Trongpanich Yanee, Phimwapi Suphaporn, Niamsanit Suwanna, Wangsomnuk P Preeya, Boonmee Mallika, Siri SineenartThe Journal of General and Applied Microbiology 11/2007; 53(5):295-9. · 0.98 Impact Factor
Article: Electrodialysis for Lactate Removal in the Production of the Dairy Starter Culture Lactococcus lactis NZ133International Journal of Food Science and Technology. 01/2006; 42:567-572.
Article: Batch and continuous culture of Lactococcus lactis NZ133: experimental data and model developmentBiochemical Engineering Journal. 01/2003; 14:127-135.