Eivind Lygren

Bio: Eivind Lygren is an academic researcher. The author has contributed to research in topics: Moving bed biofilm reactor. The author has an hindex of 1, co-authored 1 publications receiving 359 citations.

Common principles and best practices for engineering microbiomes

Abstract: Despite broad scientific interest in harnessing the power of Earth's microbiomes, knowledge gaps hinder their efficient use for addressing urgent societal and environmental challenges. We argue that structuring research and technology developments around a design-build-test-learn (DBTL) cycle will advance microbiome engineering and spur new discoveries of the basic scientific principles governing microbiome function. In this Review, we present key elements of an iterative DBTL cycle for microbiome engineering, focusing on generalizable approaches, including top-down and bottom-up design processes, synthetic and self-assembled construction methods, and emerging tools to analyse microbiome function. These approaches can be used to harness microbiomes for broad applications related to medicine, agriculture, energy and the environment. We also discuss key challenges and opportunities of each approach and synthesize them into best practice guidelines for engineering microbiomes. We anticipate that adoption of a DBTL framework will rapidly advance microbiome-based biotechnologies aimed at improving human and animal health, agriculture and enabling the bioeconomy.

Impact of Microalgae-Bacteria Interactions on the Production of Algal Biomass and Associated Compounds.

Abstract: A greater insight on the control of the interactions between microalgae and other microorganisms, particularly bacteria, should be useful for enhancing the efficiency of microalgal biomass production and associated valuable compounds Little attention has been paid to the controlled utilization of microalgae-bacteria consortia However, the studies of microalgal-bacterial interactions have revealed a significant impact of the mutualistic or parasitic relationships on algal growth The algal growth, for instance, has been shown to be enhanced by growth promoting factors produced by bacteria, such as indole-3-acetic acid Vitamin B12 produced by bacteria in algal cultures and bacterial siderophores are also known to be involved in promoting faster microalgal growth More interestingly, enhancement in the intracellular levels of carbohydrates, lipids and pigments of microalgae coupled with algal growth stimulation has also been reported In this sense, massive algal production might occur in the presence of bacteria, and microalgae-bacteria interactions can be beneficial to the massive production of microalgae and algal products This manuscript reviews the recent knowledge on the impact of the microalgae-bacteria interactions on the production of microalgae and accumulation of valuable compounds, with an emphasis on algal species having application in aquaculture

To study the performance of biocarriers in moving bed biofilm reactor (MBBR) technology and kinetics of biofilm for retrofitting the existing aerobic treatment systems: a review

Abstract: Moving bed biofilm reactor (MBBR) incorporates benefits provided by both attached and suspended growth systems. It is an advanced high rate wastewater treatment technology with high treatment efficiency; low capital, operational, maintenance and replacement cost; single reliable and robust operation procedure. Moreover, this technology is applicable to wide range of wastewater flows ranging from 10,000 to 150,000 m3 day−1. The MBBR has proved to be effective in removing up to 90 % chemical oxygen demand and 95 % biochemical oxygen demand with nutrients from the effluent stream at optimum condition, provided there is sufficient retention time. It is a cost-effective way of upgrading existing wastewater treatment system as it is efficient, compact and easy to operate. This process can be provided for new sewage treatment works or for retrofitting existing wastewater treatment plants where a higher treated effluent standard is required without any running and capital cost. The performance of MBBR depends on the percent of media provided in the reactor, surface area of the biocarrier, dissolved oxygen and the organic loading. Various mathematical models are also described in this review paper which is generally used to calculate the reactor volume, effluent organic concentration and substrate removal rate.

Effect of different operational conditions on biofilm development, nitrification, and nitrifying microbial population in moving-bed biofilm reactors

Abstract: In this study, the effect of different operational conditions on biofilm development and nitrification in three moving-bed biofilm reactors (MBBRs) was investigated: two reactors were operated in a continuously fed regime and one in sequencing-batch mode. The presence of organic carbon reduced the time required to form stable nitrifying biofilms. Subsequent stepwise reduction of influent COD caused a decrease in total polysaccharide and protein content, which was accompanied by a fragmentation of the biofilm, as shown by scanning electron microscopy, and by an enrichment of the biofilm for nitrifiers, as observed by fluorescent in situ hybridization (FISH) analysis. Polysaccharide and protein concentrations proved to be good indicators of biomass development and detachment in MBBR systems. Ammonium- and nitrite-oxidizing bacteria activities were affected when a pulse feeding of 4 g of NH4-N/(m2·day) was applied. Free nitrous acid and free ammonia were likely the inhibitors for ammonium- and nitrite-oxidiz...