Whangateau Harbour (36°19´S, 174°46´E), a shallow estuary with an area of about 7.5km2, with approximately 85% of its total area consisting of intertidal sandflats, is located approximately 70km northeast of Auckland central (Fig. 1-a) (Tricklebank et al., 2020). The amount of freshwater flowing into this place is minimal, and its tidal prism reaches a maximum of about 9,491,105 m3; over 90% of the total seawater is exchanged during each tidal cycle (Auckland Regional Council, 2009; Auckland Regional Council, 2010). Due to this environment, this area has a large community of bivalves that intake nutrients by filtering hundreds of thousands of m3 of seawater per tidal cycle (Auckland Regional Council, 2009; Burge et al., 2016).
IntroductionIf organic matter generated by human activities, such as agriculture and industry, flows into the river without any treatment, increased organic matter concentrations may cause eutrophication in the river (Shah, 2022). This causes an increase in aerobic microorganisms, such as bacteria that nourish organic matter, making it difficult for oxygen-breathing animals and plants to survive because it makes the water anaerobic (Riffat & Husnain, 2022). Humans, one of the members of the ecosystem, can also be damaged by contaminated water, so indicators are needed to measure the degree of contamination of wastewater (Radin et al., 2018). The most widely used method is Biochemical Oxygen Demand (BOD) (Riffat & Husnain, 2022).<중 략>생태계의 구성원 중 하나인 인간도 오염된 물에 의해 피해를 입을 수 있어 폐수의 오염 정도를 측정할 수 있는 지표가 필요하다. 가장 널리 사용되는 방법은 생화학적 산소 요구량(BOD)이다. 원생동물과 박테리아와 같은 호기성 이질영양생물들은 물에서 유기탄소를 분해하고 안정화시키는 과정에서 용존산소(DO)를 사용한다. 이때 일정 온도 및 시간 조건에서 유기물을 산화시킬 때 호기성 미생물이 소비하는 산소량을 측정하여 생화학적 산소요구량 또는 BOD로 정의하고, 소비하는 산소량은 mg/L 또는 ppm으로 표시한다.
IntroductionWhen the elements necessary for living things on Earth change their forms, the cycle between living and non-living environments is called the biogeochemical cycle, and the cycle of carbon, nitrogen, and phosphorus is a representative example (Bertrand et al., 2015). Since these substances do not flow from outside the ecosystem, the balance of these cycles is very important for the ecosystem maintenance (Gonzalez-Lopez & Gonzalez-Martinez, 2021).Among the elements moving through the biogeochemical cycle, nitrogen is an essential element for synthesizing proteins and nucleic acids constituting cells (Bertrand et al., 2015). Nitrogen makes up about 78% of the atmosphere, but since it is in a form that most living things cannot use, it needs to be fixed in a form that plants can use (Bertrand et al., 2015). Atmospheric nitrogen gas is converted by nitrogen-fixing bacteria into a form of nitrogen that can be used by plants (Gonzalez-Lopez & Gonzalez-Martinez, 2021).<중 략>이 실험의 목적은 토양 속의 미생물을 이용하여, 질소 순환 과정 중에서 암모니아화와 탈질 단계의 반응을 확인하는 것이다. 다시 말하면, 토양 샘플 속의 박테리아가 유기질소를 암모니아로 분해하고, 질산염을 질소 기체로 전환시킬 것이라는 가설을 확인하는 실험이다.
Cultivation<장> - 실험을 in a controlled lab environment 에서 perform 가능함- Genetic variation 을 create 해서 variable experiments 가능- Genomic analysis 를 위한 large amt of material 에 easy to access- New microbe 를 formally resister 하기 위해 pure culture 에서 배양해야 함<단> - Most of the microbe 의 present 가 miss 됨- Whole microbiome 을 analysis 할 경우 많은 time, labour 필요함- Growing in an agar plate 로 인해 microbes 의 특성이 바뀔 수 있음 e.g. a certain gene 이 switch on/off 될 수 있음- Lab environment 에서 자라지 않을 수 있음