Biochar obtained from the thermal conversion of biomass has high potential as a substitute material for activated carbon and other carbon-based materials because it is economical, environmentally friendly, and carbon-neutral. The physicochemical properties of biochar can also be controlled by a range of activation methods such as physical, chemical, and hydrothermal treatments. Activated biochar can be used as a catalyst for the catalytic pyrolysis of a biomass and as an absorbent for the removal of heavy metal ions and atmospheric pollutants. The applications of biochar are also expanding not only as a key component in producing energy storage materials, such as supercapacitors, lithium ion batteries, and fuel cells, but also in carbon capture and storage. This paper reviews the recent progress on the activation of biochar and its diverse present and future applications.

An intensive analysis was conducted of the maternal lineages of the Jeju native pigs (JNPs). A total of 100 mtDNA sequences from Asian wild boars (AWB), European wild boars (EWB), Asian domestic pigs (ADP), European domestic pigs (EDP), and JNPs were used for the phylogeny and network analyses. Two distinct JNP groups were found JNPA and JNPE in the Asian and European cluster. The maternal lineage of JNPE was the closest to that of EWB and a clear haplogroup sharing an identical haplotype (hap16) among 15 individuals of JNPE and 2 individuals of EWB was identified. However, except for hap18, no EDP shared any identical haplotypes with JNPE, suggesting that no obvious maternal contribution of EDP has occurred in JNPE in recent years. The possible existence of an additional and unknown path of maternal lineage from EDP into JNPE could therefore be postulated, in addition to those from AWB and ADP into the JNPA groups. Thus, JNPE appeared to have a pure maternal lineage that had no recent contact with EDP, and both the JNPA groups and JNPE are pure Jeju native pigs.

As a replacement for activated carbon, biochar was synthesized and used for the adsorptive removal of formaldehyde and nitrogen oxide. Biochar was produced from the fast pyrolysis of the red marine macro alga, Pyropia tenera. The P. tenera char was then activated with steam, ammonia and KOH to alter its characteristics. The adsorption of formaldehyde, which is one of the main indoor air pollutants, onto the seaweed char was performed using 1-ppm formaldehyde and the char was activated using a range of methods. The char activated with both the KOH and ammonia treatments showed the highest adsorptive removal efficiency, followed by KOH-treated char, ammonia-treated char, steam-treated char, and non-activated char. The removal of 1000-ppm NO over untreated char, KOH-treated char, and activated carbon was also tested. While the untreated char exhibited little activity, the KOH-treated char removed 80% of the NO at 50°C, which was an even higher NO removal efficiency than that achieved by activated carbon.

Refuse-derived fuel (RDF) produced using municipal solid waste was pyrolyzed to produce RDF char. For the first time, the RDF char was used to remove aqueous copper, a representative heavy metal water pollutant. Activation of the RDF char using steam and KOH treatments was performed to change the specific surface area, pore volume, and the metal cation quantity of the char. N2 sorption, Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), and Fourier transform infrared spectroscopy were used to characterize the char. The optimum pH for copper removal was shown to be 5.5, and the steam-treated char displayed the best copper removal capability. Ion exchange between copper ions and alkali/alkaline metal cations was the most important mechanism of copper removal by RDF char, followed by adsorption on functional groups existing on the char surface. The copper adsorption behavior was represented well by a pseudo-second-order kinetics model and the Langmuir isotherm. The maximum copper removal capacity was determined to be 38.17 mg/g, which is larger than those of other low-cost char adsorbents reported previously.

This study was conducted to evaluate the biopreservative potential of a bacteriocin-containing cell-free culture from Lactococcus lactis A164 on tofu. In order to increase the shelf-life of tofu, cell-free culture of A164 was added to tofu coagulant agent for coagulation process. Compared with tofu treated with distilled water, lactic acid, or cell-free culture from Lactobacillus plantarum P23, the tofu treated with a bacteriocin-containing cell-free culture from A164 could significantly suppress the number of total bacteria and extend the shelf-life of tofu. The antibacterial activity of tofu treated with cell-free culture from A164 was further evaluated by using modified agar diffusion method with Weissella paramesenteroides ATCC33313, as an indicator strain. The cell growth of the indicator strain was significantly inhibited by tofu treated with cell-free culture from A164. These results indicate that a bacteriocin-producing strain, L. lactis A164, can be used as a biopresevative for extending the shelf life of fresh-processing foods such as a tofu.

Gamma-aminobutyric acid (GABA) is a non-protein amino acid that is widely distributed in animals, plants, and microorganisms. GABA acts as a primary inhibitory neurotransmitter in the mammalian central nervous system, and is synthesized by the irreversible α-decarboxylation of acidic glutamate in the presence of glutamate decarboxylase. GABA is not only present in the central nervous system, but is also found throughout the body. GABA plays a major role in human health because it has numerous physiological functions and positive effects on many physiological disorders. Many microorganisms which possess glutamate decarboxylase have been reported to produce GABA from many food media containing glutamate. Among them, the major GABA-producers are lactic acid bacteria (LAB), which have been isolated from variety of fermented foods such as kimchi, cheese, and salted seafood. Some GABA-producing LAB strains have been shown a great potential in large-scale fermentation for the mass production of GABA by optimizing the medium composition and culture condition. In recent years, the development of natural GABA and GABA-rich products fermented by LAB is being intensively studied due to the potential health benefits of orally ingested GABA. This article is focused on the GABA-producing LAB species, GABA-rich products fermented by LAB, and health benefits of GABA-rich products.

김치 및 젓갈 등의 150여 전통 발효 식품을 시료로 하여 protease 활성을 갖는 유산균을 분리한 결과, 24 U/mgcrude protein의 높은 활성을 갖는 젖산균 BV-26 균주을 분리하였다. API 50CHL kit를 이용하여 BV-26 균주의 당 이용성을 분석하고 16S rRNA 염기서열(99.9% 상동성)을 비교한 결과, 분리된 균주를 L. plantarum BV-26으로 표기하였다. L. plantarum BV-26의 생장과 protease 활성 변화를 MRS 배지를 이용하여 측정한 결과, L. plantarum BV-26의 생장은 배양 6시간 이후 활발하게 진행되어 18시간에 최고의 균체 농도를 보였으며, protease 활성은 배양 후 12시간부터 생성되기 시작하여 16시간에서 최고의 활성을 나타내는 것으로 확인되었다. 따라서 본 연구에서 분리된 L. plantarum BV-26을 동물사료의 발효용 스타터로 이용할 경우 유산균이 갖는 유익한 장점 및 안전성을 확보할 수 있을 뿐만 아니라, 특히 대두박의 발효시 사료의 영양적 가치를 높일 수 있을 것으로 기대된다.

혈압저하작용, 이뇨기능 등의 다양한 생리활성을 나타내는 γ-amino butyric acid(GABA)를 고농도로 생산하는 유산균인 Lactobacillus sakei B2-16을 이용하여 GABA의 산업적 생산 배지를 연구하였다. L. sakei B2-16의 최적 상용 배지는 Lactobacilli MRS 배지였으며, Lactobacilli MRS 배지에 1% mono sodium glutamate(MSG)를 첨가하고, L. sakei B2-16을 배양했을 때 MSG의 99.3% 는 GABA로 전환되었다. MRS 배지를 기본으로 최적 배지조성을 검토한 결과, 탄소원으로 4% sucrose와 질소원으로 1% yeast extract를 첨가하였을 때 균체 증식과 GABA 생산량이 가장 우수하였다. 산업적 배지를 확립하기 위하여 미배아를 온수 추출하여 얻은 추출액 배지에 L. sakei B2-16을 배양한 결과, 7%의 MSG를 100% GABA로 전환시켰으며, 미배아 추출액을 이용한 배지는 산업적 생산용 배지로의 응용이 기대된다.

양파 과육부에 함유되어 있는 유용 성분인 quercetin과 그 배당체를 다양한 착즙 및 추출방법에 따른 수율을 측정, 분석하였으며 그 결과를 요약하면 다음과 같다. 양파과육의 quercetin과 배당체의 최적 추출 조건으로는 50oC에서 60% methanol를 용매로 사용했을 때 15분의 추출시간인 것으로 나왔으며 용매와 시료의 비율이 0.8 mL/g일 때 추출 수율이 가장 좋았다. 초음파를 60분 동안 처리 시 대조군에 비하여 2.06배의 추출 증가 효과를 볼 수 있었으며 microwave는 60초 조사 시에 최대의 추출 증가 효과를 나타내어 microwave를 처리하지 않은 시료와 비교하여 quercetin과 배당체가 2.14배 많이 추출되었다. 효소 처리 시 cellulase 용액과 시료의 비율이 0.5 mL/g일 때 quercetin과 배당체의 수율이 가장 높았으며 1.65 배 더 많이 추출되었고 viscozyme과 시료의 비율이 0.5 mL/g일 때 quercetin과 배당체의 수율이 가장 높았으며 추출증가율은 2.29 배인 것으로 나왔다. 가장 많은 quercetin과 배당체의 추출 수율을 보인 방법은 viscozyme과 시료의 비율이 0.5 mL/g일 때의 0.070±0.002 mg/g인 것으로 나타났다.