Characterization of the Biodiversity of the Spoilage Microbiota in Chicken Meat Using Next Generation Sequencing and Culture Dependent Approach

Hee Soo Lee,Mirae Kwon,Sunhak Heo,Min Gon Kim,Geun-Bae Kim 한국축산식품학회 2017 한국축산식품학회지 Vol.37 No.4

This study investigated the psychrotrophic bacteria isolated from chicken meat to characterize their microbial composition during refrigerated storage. The bacterial community was identified by the Illumina MiSeq method based on bacterial DNA extracted from spoiled chicken meat. Molecular identification of the isolated psychrotrophic bacteria was carried out using 16S rDNA sequencing and their putrefactive potential was investigated by the growth at low temperature as well as their proteolytic activities in chicken meat. From the Illumina sequencing, a total of 187,671 reads were obtained from 12 chicken samples. Regardless of the type of chicken meat (i.e., whole meat and chicken breast) and storage temperatures (4°C and 10°C), Pseudomonas weihenstephanensis and Pseudomonas congelans were the most prominent bacterial species. Serratia spp. and Acinetobacter spp. were prominent in chicken breast and whole chicken meat, respectively. The 118 isolated strains of psychrotrophic bacteria comprised Pseudomonas spp. (58.48%), Serratia spp. (10.17%), and Morganella spp. (6.78%). All isolates grew well at 10°C and they induced different proteolytic activities depending on the species and strains. Parallel analysis of the next generation sequencing and culture dependent approach provides in-depth information on the biodiversity of the spoilage microbiota in chicken meat. Further study is needed to develop better preservation methods against these spoilage bacteria.

The Growth of Proteolytic Bacteria Immobilized in Capsule Type

Han Bong-Ho,Choi Su-Il,Kim Seong-Bong,Kim Sang-Ho The Korean Society of Fisheries and Aquatic Scienc 1999 Fisheries and Aquatic Sciences Vol.2 No.1

Proteolytic bacteria isolated from fermented anchovy jeotkal were immobilized in capsule type with $0.8\%$ sodium alginate and $CaCl_2/carboxymethyl$ cellulose (CMC). For making the immobilized capsule, the optimal concentration of both $CaCl_2$ and CMC, with respect to the membrane hardness and the growth of proteolytic bacteria in capsule, were $2.0\%$ at following conditions: flow rate of $CaCl_2/CMC$ solution and cell suspension were respectively 3.54 ml/min and 0.15 ml/min when inside diameter of inner and outer capillary tube in immobilizing apparatus were 0.32mm, 0.74mm, respectively. The density of proteolytic bacteria in capsule reached maximum, i.e. $10^8-10^9cells$/capsule during culture under optimal conditions in TPY broth, and these were $10^2-10^4$ times higher than these of before culture. During culture of proteolytic bacteria immobilized in capsule type (PBImC) for 72hrs, few growing cells were lost in the outer medium.

Characterization of the Proteolytic Activity of Bacteria Isolated from a Rotating Biological Contactor

박인재,JerngChangYoon,SeongJooPark,EungHoKim,Yeon-JaeCho,Kwang-SooShin 한국미생물학회 2003 The journal of microbiology Vol.41 No.2

Four proteolytic bacteria were isolated and identified from a rotating biological contactor based on Bacillus. The four isolates, Ni 26, 36, 39 and 49 were identified as B. vallismortis, B. subtilis, Aeromonas hydrophila and B. amyloliquefaciens, respectively, based on their biochemical properties and 16S rDNA sequence analyses. The optimal proteolytic activity was observed in the temperature and pH ranges of 40-70ºC and 8.0-8.5, respectively. The proteolytic activities of all the isolates were partially inhibited by phenylmethylsulfonylfluoride (PMSF), and the isolates Ni 26, Ni 39 and Ni 49 were inhibited by the metalloprotease inhibitor, 1,10-phenanthroline. Zymographic analyses of the culture supernatants revealed the presence of at least two proteases in all isolates.

A Study on the Rapid Hydrolysis of Fish Using Proteolytic Bacteria Isolated from Anchovy Jeotkal

Kim Sang-Ho,Kim Young-Min,Seong Hee-Kyung,Choi Su-Il,Kim Seon-Bong,Han Bong-Ho The Korean Society of Fisheries and Aquatic Scienc 1999 Fisheries and Aquatic Sciences Vol.2 No.1

A study on the hydrolysis of anchovy using proteolytic bacteria isolated from anchovy jeotkal (a salt-fermented fish) was carried out to develop a rapid process of liquefied anchovy jeotkal. Five kinds of proteolytic bacteria, such as Staphylococcus sp.-l, Photobacterium sp., Volcaniella sp., Staphylococcus sp.-2 and Bacillus sp., were isolated from the anchovy jeotka1 that fermented with $20\%$ NaCl at room temperature for 2 months. Those grew well at $40^{\circ}C$, pH 7.0 on TPY broth with $2.0\%$ NaCl. The optimal hydrolysis temperature, pH, time and proteolytic bacteria densities for hydrolysis of minced anchovy were$40^{\circ}C$, 7.0, 6 hours and $1.8\times10^8$ cells/g raw anchovy, respectively.

유산균의 Casein Phosphopeptide(CPP) 생산 및 단백질 분해 활성

조윤희,오세종,Cho, Yoon-Hee,Oh, Se-Jong 한국축산식품학회 2010 한국축산식품학회지 Vol.30 No.3

Casein phosphopeptide (CPP) enhances calcium absorption in humans. Lactic acid bacteria (LAB) are capable of synthesis of cell-surface proteinase, which can hydrolyze milk protein and release several types of peptides in the medium. This study was conducted to characterize proteinase of LAB and to evaluate the CPP production from bovine milk. The content of CPP of milk produced by cell-free extract of LAB was determined based on the quantity of decomposed peptide from casein using the O-phthaldialdehyde (OPA) method. The proteolytic activity of LAB was assayed using fluorescein isothiocyanate (FITC)-labeled casein. Casein appeared to be a better substrate than whey proteins for extracellular proteinases of LAB. During fermentation, milk proteins were hydrolyzed by extracellular proteinase of LAB, resulting in an increase in the amount of free $NH_3$ groups. Overall, the results presented here indicate that CPP produced by LAB may be a promising material for novel applications in the dairy industry.

계절에 따라 여러 지역의 원유에서 분리된 내냉성 미생물의 효소 활성

신용국,오남수,이현아,남명수,Shin, Yong Kook,Oh, Nam Su,Lee, Hyun Ah,Nam, Myoung Soo 한국축산식품학회 2013 한국축산식품학회지 Vol.33 No.6

지방분해효소 활성이 가장 높은 균은 가을철에 집유한 B 지역의 원유로부터 분리한 Acinetobacter genomospecies 10(match %: 99.90)이었으며, 단백질분해효소 활성이 가장 높은 균은 봄철에 B 지역의 원유로부터 분리한 Serratia liquefaciens(match %: 99.39)였다. Acinetobacter genomospecies 10(match %:99.90)는 전형적인 생장곡선의 형태인 시그모이드 곡선의 형태를 나타냈으며, 배양시간별 조효소 활성은 배양시간이 증가할수록 지방분해효소 활성이 증가하다가 정지기 후반부에서부터 사멸기에 도달하기까지는 배양시간이 길수록 활성이 감소하였다. pH에 따른 지방분해효소 활성은 pH 8.5에서 가장 높았고 온도는 $45^{\circ}C$에서 가장 높은 활성을 나타내었다. Serratia liquefaciens(match %: 99.39)의 생장곡선은 전형적인 시그모이드 형태를 나타내었고, 단백질분해효소 활성은 배양 12시간 후에 가장 높았고, 18시간 후에는 다시 감소하는 양상을 나타냈다. 단백질 분해효소의 pH 영향은 2.5에서 활성이 가장 낮았고 pH 8.5에서 가장 높은 활성을 나타내었다. 또한 반응온도에 의한 효소활성은 $35^{\circ}C$에서 가장 높았다.

전통 김치로부터 Probiotic 유산균의 분리 및 우유 발효 특성

임영순,김지연,강현철 한국낙농식품응용생물학회 2019 Journal of Dairy Science and Biotechnology (JMSB) Vol.37 No.2

Lactic acid bacteria obtained from traditional Kimchi were selected on the basis of their caseinolytic activity and lactose usability and examined for availability as a starter in probiotic activity. Thirty-two strains were selected as lactic acid producing bacteria in BCP agar, and two strains (KC23 and KF26) with more than 90% resistance for both acid and bile salts were selected. The two strains were identified as L. plantarum (KC23) and L. paracasei (KF26) by API 50 CHL system and 16S rRNA sequence analysis. L. plantarum (KC23) was finally selected based on its biochemical characteristics for lactose and raffinose usability. Free tyrosine content increased rapidly in 10% skimmed milk medium, from 24.1 μg/mL after 8 h to 43.9 μg/mL after 16 h. Additionally, the caseinolytic clear zone of 12 mm of L. plantarum (KC23) was greater than the 9 mm zone of commercial L. acidophilus CSLA. The bacterium exhibited mesophilic growth and yielded 8.9×108 CFU/mL when incubated at 37°C for 12 h at pH 4.25. Moreover, L. plantarum KC23 exhibited antibacterial activity as it formed a clear zone of 8–13 mm for the 5 pathogens. Adherent activity was 2.23 fold higher than that of LGG. The acidity of 10% skimmed milk fermented for 12 h was 0.74%.

우모 분해균의 분리 및 특성에 관한 연구

강호조,이후장,정태성,김도경,어용준,김재황 한국수의공중보건학회 2003 예방수의학회지 Vol.27 No.3

Feather waste, generated in large quantities as a byproduct of commercial poultry processing, is almost pure keratin, which is not easily degradable by common proteolytic enzymes. Several feather-degrading bacterial isolates were isolated from feather waste and soil. These isolates were able to degrade chicken feather, when grown on basal medium containing 1.0% native feather as a source of energy, carbon, and nitrogen. The isolates were characterized according to morphological characteristics and biochemical tests, and Vitek and API kit system. belonging to the Acinetobacter calcoaceticus complex, Bacillus thuringiensis, Bacillus circulans, Bacillus cereus. It was observed that aerobic growth by the isolate on single whole chicken feather, resulted in complete degradation of the keratin protein after 5-6 days of incubation at 37℃. The production of protein by the organism was decreased with cultivation time, with the maximum activity coinciding with the start of the stationary phase. The kerationolytic activity increased with cultivation time.

Comparative Analysis of the Morphology and Composition of Chitin Extracted from Mealworms Using Chemical and Biological Methods

송용수,안성규,정우진 한국키틴키토산학회 2024 한국키틴키토산학회지 Vol.29 No.1

This study investigated the changes in the amino acid composition of mealworm substrates incubated separately with Bacillus subtilis EG1 and Leuconostoc mesenteroides BW2 cultures. The results revealed a reduction in the levels of 16 and 17 amino acids in the B. subtilis EG1 and L. mesenteroides BW2 treatments, respectively. The internal and external morphologies of mealworm chitin obtained after treatment with B. subtilis EG1 and L. mesenteroides BW2 cultures were investigated using light and polarized microscopy. Notably, protein removal from the exoskeleton was more effective with prolonged culture periods in the proteolytic bacterium B. subtilis EG1. Furthermore, Fourier-transform infrared (FT-IR) spectroscopy analysis indicated that the functional groups of chitin exhibited almost identical spectra across all treatments. The amino acid compositions of two mealworm types, Before Oil Extraction (BOE) and After Oil Extraction (AOE), cultured with B. subtilis EG1, were also investigated. Both BOE- and AOE-type mealworms exhibited the highest glutamic acid content and the lowest cystine content on day 0. Moreover, protein content in the exoskeleton of both BOE- and AOE-type mealworms decreased as the culture period with B. subtilis EG1 increased, as observed through light and polarized microscopy.