Biological Systems Unit
Professor Igor Goryanin



For last years, the Biological Systems Unit has been engaged in development of BioElectrochemical System (BES)/Microbial Fuel Cell (MFC) technology for wastewater treatment. The BES/MFC applies complex interactions between microbial populations and electrodes to remove organics and to generate electricity, merging basic and applied goals of our Unit. Utilizing biological, chemical, engineering, and bioinformatics approaches, the Unit seeks to improve BES/MFC systems for better treatment efficiencies and electricity generation by understanding and building ideal microbial communities and developing cost-effective materials. Sustainable wastewater treatment is especially important for small islands like Okinawa.

One of the challenges of this technology is scaling up. The Unit has been working with a local Awamori (Okinawa unique spirit) distillery for the past nine years to treat rice wash and distillery wastewater. David Simpson, Tech Pioneer Fellow from OIST Business Development Section continued to apply his newly developed reactors for the treatment of Awamori rice and distillery wastes for mid- and small factories and established a start-up company “Watasumi”.

The Unit continued developing technology for removing organics, odor, nitrogen, and phosphate from raw and aerated swine wastewater using biocathode system. The 65L demonstration reactors were monitored at the Okinawa Prefecture Grassland and Livestock Research Center and improvements were made. We have received established a new collaboration with NIKKO company who produce and sell Jokaso (a Japanese registered domestic wastewater treatment system), and together designed a scale-up reactor with improved water engineering technology and received various advice on commercialization.  We focus on the scaling up of the technology and seeking additional funding and collaborations.

1. Staff

  • Dr. Igor Goryanin, Professor
  • Dr. Mami Kainuma, Group Leader
  • Dr. Peter Babiak, Staff Scientist
  • Mr. Takuro Kometani, Technician
  • Ms. Shizuka Kuda, Research Unit Administrator

2. Collaborations

2.1 Air Cathode development

  • Type of collaboration: Joint research and development
  • Collaborator:
    • Toyo INC SC

2.2 An advanced wastewater treatment technology development for swine farms

  • Type of collaboration: Joint research and development
  • Collaborators:
    • Okinawa Prefecture Environmental Science Center
    • Okinawa Prefecture Grassland and Livestock Research Center
    • NIKKO Company

3. Activities and Findings

3.1 R&D on swine wastewater treatment technology for simultaneous removal of nitrate and organics using bioelectrochemical systems (BES)

The volume of wastewater produced by intensive pig farming in Okinawa surpasses the available capacity for treatment and recycling. Removal of nitrate from wastewater is a worldwide concern due to its negative effects on human and environmental health. Currently the nitrate-nitrogen discharge limit for livestock wastewater receives special measure (500 mg/L) but in the very near future it will be lower to the general discharge standard (100 mg/L) to meet all other industries. Hence, cost-effective nitrate removal in livestock industry is the urgent issue in Japan. According to interviews we conducted with local swine farmers, we also identified operating cost as a serious drawback of the current aeration-based technology with high electricity cost and the cost of chemicals for coagulating excess sludge, which combined account for 60-80% of the running cost.

Since May, 2019, two pilot-scale two-chambered biocathode reactors (58 L active volume) have been running at Okinawa Prefecture Grassland and Livestock Research Center and monitored for nearly three years at continuous mode. The system simultaneously treated organics and nitrate in real swine wastewater. The raw wastewater contains high organic and volatile fatty acid levels (responsible for malodors) that are oxidized by the microbial community in the anode chamber, which lowers the time need for aeration and removes smells. Under applied potential, electrons are transferred to the cathode, where nitrate in aeration-treated wastewater (nitrified) serves as an electron acceptor and is converted to dinitrogen by denitrification via the cathodic microbial community. The advantage of this system is in allowing denitrification to operate at a low wastewater COD/N ratio. One of the issues we encountered during the operation was the corrosion of stainless-steel core of anode carbon brush electrodes. To overcome for the future scale up, we first tested the carbon fibers without stainless steel core in 2L lab-scale reactors and confirmed no major difference in removal of organics/nitrate. Then we further tested in the pilot scale reactor on site and demonstrated the removal of organics (more than 1g COD/L/day) were equivalent to the carbon brush used originally but with longer lifespan. 

Two approaches were tested for phosphate removal: First was electrocyclization. Phosphate was precipitated on cathode carbon fiber electrodes as a form of calcium phosphate. Phosphate was removed down to standard discharge level (16 mg/L) from aerated wastewater. Phosphate was possible to recover by washing electrodes in acidic conditions.

The second approach was pretreatment of aerated wastewater by phosphate precipitation with Fe3+/Fe2+ ions. These ions were solubilized from iron electrodes (commercially available) and was precipitated as iron phosphate. The phosphate concentration was brought down to 1.3 mg/L prior to the inflow into our BES reactors. Pretreatment method will allow to prolong maintenance intervals of cathode electrodes.

We have established a new collaboration with NIKKO company with the goal of commercializing our technology.  A new blueprint of the scale-up reactors was produced by incorporating their expertise in water treatment engineering and improving maintenance efficiency.  The new scale-up reactors will be constructed next year to test on-site.


The project was supported by Okinawa Science and Technology Innovation Ecosystem Construction fund and Proof of Concept I (OIST), and the provisional patent application submitted.

Featured news articles:
Newspaper: Okinawa Times (May 26, 2021) and Ryukyu Shimpo (May 26, 2021)

3.1.2  96-well MFC array

A high-throughput 96- well array of Microbial Fuel Cells (MFCs) was constructed. Capability to enrich electroactive acid mine drainage communities was demonstrated.96-well plate MFC was used as a tool to enrich the consortia and scale up the process. Electroactive consortia treated toxic copper concentrations with 50% of Cu removal. Out technology could be used for industrial waste management especially and metal accumulation [1,2].

3.1.3 MFC biosensors

The measurement method consists of batch sample injection, continuous measurement of cell voltage and calculation of total charge (Q) gained during the biodegradation of organic content. Diverse samples were analysed: acetate and peptone samples containing only soluble readily biodegradable substrates; corn starch and milk samples with suspended and colloidal organics; real domestic and brewery wastewaters. Linear regression fitted to the Q vs. BOD5 measurement points of the real wastewaters provided high (> 0.985) R2 values. Time requirement of the measurement varied from 1 to 4 days, depending on the composition of the sample. Relative error of BOD measured in the MFCs comparing with BOD5 was less than 10%, thus the method might be a good basis for the development of on-site automatic BOD sensors for real wastewater samples [3,4]

3.1.4 Microbiome analysis, COVID

The digestive system is an environmental frontline involving digestive secretions, intestinal cell metabolism, and gut microbiome that significantly modulate multiple functions in organisms. Understanding the ‘gut-lung axis’, where gut residential microbiota play important roles, may help in the development of better prophylactics and intervention strategies for diseases caused by respiratory viruses, including coronavirus disease of 2019 (COVID-19). Gastrointestinal symptoms are common in COVID-19 patients and are generally indicative of disease complications. This review presents evidence of microbiome signatures in the gut and respiratory system that may predict the severity and long-term outcomes of COVID-19. Understanding the factors (such as pro-inflammatory trends, modulation of metabolite availability, and impact on cell signalling and pathogenic properties) translating the effect of microbiome composition on the severity of respiratory infections should help in the development of new approaches for health monitoring, disease prevention, and treatment. [6]

3.1.5 AI and Passive Microwave Radiometry (MWR). Venous diseases and COVID

First time Passive Medical Radiometry (MWR) and AI have been used to identify venous disease patients with sensitivity above 0.8 and a specificity above 0.7. We studied the possibility of using artificial intelligence (AI) passive microwave radiometry (MWR) for the diagnostics of venous diseases. MWR measures non-invasive microwave emission (internal temperature) from human body 4 cm deep. The method has been used for early diagnostics in cancer, back pain, brain, COVID-19 pneumonia, and other diseases. In this paper, an AI model based on MWR data is proposed. The model was used to predict the disease state of phlebology patients. We have used MWR and infrared (skin temperature) data of the lower extremities to design a feature space and construct a classification algorithm. Our method has a sensitivity above 0.8 and a specificity above 0.7. At the same time, our method provides an advisory outcome in terms which are understandable for clinicians. [7]

We tested MWR use first time for the early diagnosis of pulmonary COVID-19 complications in a cross-sectional controlled trial in order to evaluate MWR use in hospitalized patients with COVID-19 pneumonia and healthy individuals. We measured the skin and internal temperature using 30 points identified on the body, for both lungs. Pneumonia and lung damage were diagnosed by both CT scan and doctors’ diagnoses (pneumonia+/pneumonia−). COVID-19 was determined by RT-PCR (covid+/covid−). The best MWR results were obtained for the pneumonia−/covid− and pneumonia+/covid+ groups. The study suggests that MWR could be used for diagnosing pneumonia in COVID-19 patients.[8]

3.1.6 Passive Microwave Radiometry (MWR) for brain disorder, spine.

Brain temperature (BT) is a crucial physiological parameter used to monitor cerebral status. Physical activities and traumatic brain injuries (TBI) can affect BT; therefore, non-invasive BT monitoring is an important way to gain insight into TBI, stroke, and wellbeing. The effects of BT on physical performance have been studied at length. When humans are under extreme conditions, most of the energy consumed is used to maintain the BT. In addition, measuring the BT is useful for early brain diagnostics. Passive microwave radiometry (MWR) measures the intrinsic radiation of tissues in the 1–4 GHz range. It was shown that non-invasive passive MWR technology can successfully measure BT and identify even small TBIs. [9]

Evaluation of the effectiveness of treatment of nonspecific lower back pain (LBP) is currently largely based on the patient's subjective feelings. The purpose of this study was to use passive microwave radiometry (MWR) as a tool for assessing the effectiveness of various treatment methods in patients with acute and subacute nonspecific LBP.[10]

Microwave Radiometry (MWR) has the advantage that measurements of internal (i.e. deep) tissue temperature may be obtained non-invasively by measuring naturally emitted radiation in GHz range. The goal of the study is to further the development of MWR for clinical application in assessment of patients with Low Back Pain (LBP). In particular, a protocol was developed in which MWR was used to measure internal temperature at the level of the spinous processes of the L1 to L5 vertebral bodies along median and left and right para-vertebral lines. Analysis revealed there to be a significant increase in deep tissue temperature with increasing pain severity as measured by using a Visual Analogue Scale (VAS) in patients with LBP (p < 0.05). In conclusion, MWR potentially allows for objective assessment of the magnitude of clinical symptoms in patients with LBP and shows promise for measuring pain severity.[11]

3.1.6 Passive Microwave Radiometry (MWR) MWR. New developments

We present a new circuit of the miniature microwave radiometer for wearable devices, which can be used to monitor the core body temperature (CBT) of internal human tissues continuously 24/7. The measurement results of the proposed device, as opposed to the known miniature wearable radiometers, remain unchanged when the impedance of the examined area varies. We have derived an analytical expression for radiometer measurement error based on parameters of device components. This formula allows accuracies to be estimated and optimal parameters of the circuit to be selected to minimise measurement error at a design stage. It is shown that measurement error is independent of the antenna reflection coefficient and the temperature of the radiometer front-end. A prototype of the single-channel miniature radiometer has 32 × 25 × 14 mm3 dimensions and USB interface communication with PC. A 28 -h run of the device has shown that it is highly stable [12]

4. Publications

4.1 Journals

  1. High-throughput 96-well bioelectrochemical platform for screening of electroactive microbial consortia L Szydlowski, J Ehlich, I Goryanin, G Pasternak Chemical Engineering Journal 427, 131692,2 2022
  2. High-throughput screening and selection of PCB-bioelectrocholeaching, electrogenic microbial communities using single chamber microbial fuel cells based on 96-well plate array. J Ehlich, N Shibata, I Goryanin, Preprints, 2021
  3. Microbial fuel cell biosensor for the determination of biochemical oxygen demand of wastewater samples containing readily and slowly biodegradable organics, GM Tardy, B Lóránt, M Gyalai-Korpos, V Bakos, D Simpson, I Goryanin, Biotechnology letters 43 (2), 445-454, 6, 2021
  4. Application of Air Cathode Microbial Fuel Cells for Energy Efficient Treatment of Dairy Wastewater,  B Lóránt, M Gyalai-Korpos, I Goryanin, GM Tardy, Periodica Polytechnica Chemical Engineering 65 (2), 200-209, 1, 2021
  5. Concurrent treatment of raw and aerated swine wastewater using an electrotrophic denitrification system A Prokhorova, M Kainuma, R Hiyane, S Boerner, I Goryanin, Bioresource technology 322, 124508, 4, 2021
  6. The Gut Microbiome versus COVID-19, O Vasieva, I Goryanin,  Journal of Computer Science and Systems Biology 14 (1), 1-8, 1, 2021
  7. Using AI and passive medical radiometry for diagnostics (MWR) of venous diseases V Levshinskii, C Galazis, A Losev, T Zamechnik, T Kharybina, S Vesnin, ...I. Goryanin, Computer Methods and Programs in Biomedicine 215, 106611, 1        , 2022
  8. Passive microwave radiometry for the diagnosis of coronavirus disease 2019 lung complications in Kyrgyzstan B Osmonov, L Ovchinnikov, C Galazis, B Emilov, M Karaibragimov, ... I Goryanin Diagnostics 11 (2), 259, 5, 2021
  9. Using medical microwave radiometry for brain temperature measurements O Shevelev, M Petrova, A Smolensky, B Osmonov, S Toimatov, ...I Goryanin, Drug Discovery Today, 1, 2021
  10. Treatment and Companion Diagnostics of Lower Back Pain Using Self-Controlled Energo-Neuroadaptive Regulator (SCENAR) and Passive Microwave Radiometry (MWR) AV Tarakanov, AA Tarakanov, T Kharybina, I Goryanin Diagnostics 12 (5), 1220, 2022
  11. Microwave Radiometry (MWR) temperature measurement is related to symptom severity in patients with Low Back Pain (LBP) AV Tarakanov, AA Tarakanov, S Vesnin, VV Efremov, I Goryanin,…Journal of Bodywork and Movement Therapies 26, 548-552, 1, 2021
  12. Portable microwave radiometer for wearable devices, SG Vesnin, MK Sedankin, LM Ovchinnikov, AG Gudkov, VY Leushin, ... I. Goryanin  Sensors and Actuators A: Physical 318, 112506, 10, 2021
  13. Passive Microwave Radiometry (MWR) as a Component of Imaging Diagnostics in Juvenile Idiopathic Arthritis (JIA) AV Tarakanov, ES Ladanova, AA Lebedenko, TD Tarakanova, SG Vesnin, ...I Goryanin, Preprints. 2021
  14. Monitoring Protein Denaturation of Egg White Using Passive Microwave Radiometry (MWR) I Goryanin, L Ovchinnikov, BT Kobayashi, SG Vesnin, YD Ivanov, Preprints, 2, 2021
  15. Cohen MF, Kubota CM, Quintero Plancarte G, Kainuma M (2021) Biological polishing of liquid and biogas effluents from wastewater treatment systems. In: Integrated and hybrid technology for water and wastewater treatment. Ang WL, Mohammad A., Eds., Elsevier, ISBN: 595806, p.87-98. https://doi.org/10.1016/B978-0-12-823031-2.00010-0.

4.2 Oral and Poster Presentations

  1. Prokhorova, A*., Hiyane, R., Kazeoka, M., Ninomiya, I., Goryanin, I and Kainuma, M. Bioelectrochemical treatment of livestock wastewater in pilot-scale; opportunities and challenges. The 5th Asia Pacific-International Society for Microbial Electrochemical Technology July 16-18,m 2021. Harbin, China.
  2. Babiak, P*., Schaffer-Harris, G., Murzabaev, M., Kainuma, M., Simpson, D., Miyasfusa, Y., Goryanin, I.  Comparison of different air cathode designs. The 5th European meeting on International Society for Microbial Electrochemistry and Technology September 2021
  3. Kainuma, M*., Prokhorova, A., Babiak, P.,  Hiyane, R. Kazeoka, M., Ninomiya, K., Goryanin I. Advanced wastewater treatment technology development for swine farms using bioelectrochemical systems. Resource utilization and water environment in Tropical/sub-tropical region. Japan Society on Water Environment, September 14, 2021. 生物電気化学法による養豚場排水の高度処理技術開発 水環境学会 熱帯亜熱帯地域の地域資源の利活用と水環境
  4. Kainuma, M. Environmentally friendly advanced wastewater treatment system, Okinawa Science and Technology Innovation System Construction (Feb. 2022 On demand) 沖縄科学技術イノベーションシステム構築事業研究発表会(オンデマンド配信)

4.3 Patents

  1. Babiak, P., Schaffer-Harris, KG., Kainuma, M. and Goryanin, I. Method for treating wastewater and wastewater treatment system JP2021-090950
  1. Kainuma, M., Prokhorova, A., Hiyane, R., Kazeoka, M. Goryanin, I. and Babiak, P. Concurrent raw and aerated wastewater treatment method using bioelectrochemical system. JP2021-18297

5. Grants received

The overall objective of the MFC/BES projects is to introduce a new technology for the sustainable development of livestock industry. Our efficient low-maintenance wastewater treatment system will lower operational costs while allowing farmers to meet impending regulations on discharges of nitrogen and phosphate.

  • Proof of Concept (POC)1 FY2021.  An advanced wastewater treatment and nutrient recovery for swine farms
  • Okinawa Science and Technology Innovation System Construction Fund. FY2021 Development of environmentally concerned wastewater treatment system with simultaneous removal of organics, nitrate and malodors.