The clogging phenomenon in the fixed film reactor is shown when biomass growth is excessive for long operating time. In addition, effluent water quality gets worse because of detachment of biomass. In this study, we conducted air - backwashing to sustain biomass in reactor to complement these defects. The results of experimental are showed in the following conclusion. The detachment rate was 19.5 - 38.0 % when the organic loading rate was 0.40 - 1.32 ㎏ COD/㎥/day, the air - backwashing intensity was 2 L/min(6.7 ㎥/㎡/hr) and the backwashing time was 15 - 19 seconds. And the detachment rate was 32.2 - 58.6 % when the organic loading rate was 1.37 - 2.27 ㎏ COD/㎥/day, the backwashing time was 1 - 12 minutes. As organic loading rate and backwashing time are increased, detachment of fixed biomass is increased. The detachment equation with detachment rate(DR, %), backwashing time(BWT, min), fixed biomass concentration(FB, ㎎/L), and organic loading rate(OLR, ㎏ COD/㎥/day) through multiple linear regression was given by the following equation: DR = 17.964 BWT^0.41407 FB^0.0597 OLR^0.1945

To investigate the antimicrobial activities and effect of grapefruit seed extract(GFSE) on the physiological function of microorganism, antimicrobial activity, fatty acids of bacterial cell lipid and amino acids of bacterial cell protein were measured. The change of cell morphotype was observed by transmission electron microscope. GFSE was very stable on the wide range temperture and pH. The growth rate of E. coli and B. suvtilis were decreased above 40ppm GFSE There fore, minimum inhibitory concentration (MIC) of the E. coli and B. subtilis to GFSE were determined around 40ppm. In the change of fatty acids quantities, hexadecanoate was significantly decreased on the treatment compared with control in case of E. coli, whereas tridecanoate was not detected in case of B. subtilis. In the change of amino acids quantities, alanine, glutamic acid, glycine, lysine were decreased on the treatment compared with control in case of E. coli and B. subtilis Transmission electron microsgraphs(TEM) showed the microbial cells were destroyed by GFSE.

In order to develovpment of new sterilizing method applied to food industry, effects of ozone treatment on microorganisms, associated with food hygiene were investigated. Microorganisms were immersed in water and sparged with ozonised air(ozone concentration, 3mg liter-1) at an air flow rate of 5 liter min-1. When organisms were treated with benzoic acid and sorbic acid of 0.4∼1.0g/, respectively, they were not dectable perfectly. Sodium benzoate had an effect on Penicillium islandicum. When bacteria were sparged with ozonised air, Pseudomonas aeruginosa completely inhibited at 60 minutes, and the killing Aspergillus flavus and Penicillium islandicum. Also, all of bacteria were inactivated after immersed with ozonated water for 10minutes, but two fungal species were not effective.

This paper was carried out to investigate change in the initial microorganism of Pepper which were treated with ozonated water for microbial decontamination. When ozonated water was 30, 60, 90minutes treatment, there was decrease in the overall total microbial of the black & white pepper. Total lactic acid bacteria died completely after contacted with ozonated water for 60minutes but the inhibition rate on the total aerobic bacteria of black & white pepper were 62% and 96%, respectively. Total aerobic bacteria of four packing material was increased after 1 months of storage at 37 when it had treated with 90minutes ozone reaction Then, there was no significant changes in the piperin contents.

Spices(Tumeric, Celery-seed, Cumin, Black pepper, Coriander) were irradiated at dose levels of 0, 5, 7 and 9kGy using Co60 source and stored at room temperature. After 12 months of storage following 9kGy irradiated spice, total aerobic bacteria were significantly decreased. When the irradiation dose was 7kGy, microbial levels showed l02-103 levels. However, total lactic acid bacteria and E-coli were shown negative at below 5kGy.

In order to obtain basic data for the development of Gat-Kimchi, a salted and fermented lear mustard, changes in mineral, pigment, texture, sensory score and microflora during fermentation at 52 were investigated. Changes in mineral, including iron, calcium and potassium were obviously shown and their contents were markedly decreased after 14 days of fermentation. Contents of total chlorophyll and carotenoid were slowly decreased after 6 and 10 days of fermentation, respectively and ratios of chlorophyll a/b were not changed and similar to those of other cruciferous vegetable Kimchi during fermentation. Shear force of Gat-Kimchi in rheometer during fermentation was increased. The sourness and hardness(p

A number of experiments were conducted in order to investigate the organic removal efficiency and biomass characteristics according to the organic shock loading rate in a fluidized bed biofilm reactor. At the operation conditions of HRT, 8.44 hour, superficial upflow velocity, 0.9 ㎝/sec and temperature, 22±1 ℃, the removal efficiency of SCOD was founded to be 96.5, 92 and 90 % with the organic shock loading rate of 3.5, 10.8 and 33 kgCOD/㎥·day, respectively. Within the F/M ratio ranged 0.4 to 2.0 ㎏COD/㎏VSS·day, the SCOD removal efficiency was shown as 90% at F/M ratio of 2.0 ㎏COD/㎏VSS·day, but the TCOD removal efficiency was 72 % at F/M ratio of 1.8 kgCOD/kgVSS·day. The average biomass concentrations were 7800, 14950 and 27532 ㎎/l on the organic shock loading rate of 3.5, 10.8 and 33 ㎏COD/㎥·day, respectively. This result was agreed with the fact that more biomass could be produced at high concentration of substrate, but some biomass was detached at the onset of shock and easily acclimated at the shock condition.

With the soil samples collected from 33 locations in Kwangju area, the physiochemical properties of soil and soil microorganisms have been studied and the results of'the analysis were as follows ;1 . Tlle temperatilre, pH, moisture and organic matter of sampling s'tes were measured in the range of 21.O~28.O℃, 4.0"6.6, 2.1"24.0% and 2.8~22.0% respectively.and that showed wide range distribution in moisture and organio mattrr particulary.and averase was 24.℃ of temperature, 4.9 of pH, 11.9% of moisture and 8.9% of'organic matter.2. The general bacterial number, cellulolytic bacterial number, general fungal number and cellulolytic fungal number were measured in tile range of 23×10[-995] 1548x10[-995] , 8.0×10[-995] ~412.0×10[-995] , 0.3×10[-994] ~56.4×10[-994] and 0.Ix10[-994] ~17.2x10[-994] , respectivelyand average was 378.4×10[-995] of general bacteria, 102.5×10[-995] of cellulolytic bacteria.13.OX10[-994] of general fungi and 4.3×10[-994] of cellulolytic fungi.tic fungi.