Rasma Tretjakova, Lyubomir Lazov, Andris Martinovs, Samanta Marija Misiņa


At the biogas plant total of 40 digestate samples have been collected and investigated. The microbiological composition of digestate has been analysed before and after laser processing with wavelength λ 445 nm with power 2 - 4 W. Salmonella spp. has not been stated in any of the samples, Escherichia coli and Enterococcus spp. amount does not correspond Eiropean Union regulation R142/2011 requirements in any of the investigated samples; Staphylococcus aureus has been stated in 24 samples out of 40. By decreasing laser scanning speed and increasing power, the total number of microorganism colonies in digestate has decreased.


laser; digestate; bacteria

Full Text:



Goberna M. , Podmirseg S.M., Waldhuber S., Knapp B.A., García C., Insam H., "Pathogenic bacteria and mineral N in soils following the land spreading of biogas digestates and fresh manure," Applied Soil Ecology, vol. 49, pp. 18–25, 2011.

Bioenergy, Association of New Zeland Inc. The production and use of digestate as fertiliser. Banz Technicalguide. 2013.

Svensson K., Odlare M., Pell M. "The fertilizing effect of compost and biogas residues from source separated household waste," Agric. Sci., vol. 142, pp. 461–467, 2004.

Gómez-Brandón M. , Fernández-Delgado Juárez M., Zangerle M., Insam H. "Effects of digestate on soil chemical and microbiological properties: A comparative study with compost and vermicompost," Journal of Hazardous Materials, vol. 302, pp. 267–274, 2016.

Studer I., Boeker C., Geist J. "Physicochemical and microbiological indicators," Ecological Indicators, vol. 77, pp. 314–322, 2017.

Pulvirenti A., Ronga D., Zaghi M., Rita A., Mannella T., Pecchioni N. "Pelleting is a successful method to eliminate the presence of Clostridium spp. from the digestate of biogas plants", Biomass and Bioenergy," vol. 81, pp. 479–482, 2015.

Migliorati E. K. J. Lasers and bacterial reduction: A comprehensive technique to treat chronic periodontitis. [Online]. Available: [Accessed: 01.02.2017.].

Stepp H., Andersson-Engels S. "Editorial Therapeutic laser application and tissue interactions: Bringing light into clinical practice," Biophoton, vol. 3 (5–6), pp. 259–260, 2010.

Lavrentjeva L.V., Avdeev S. M., Sosnin E. A., Velicevskaja K. J. "Analysis of excilamps UV radiation bactericide action on pure microorganism cultures," Tomsk State University Journal of Biology, vol. 2(3), pp. 18-27, 2008. Лаврентьева Л.В., Авдеев С.М., Соснин Э.А., Величевская К.Ю. 2008. Бактерицидное действие ультрафиолетового излучения эксимерных и эксплексных ламп на чистые культуры микроорганизмов. Вестник

Томского государственного университета. Биология. 2(3): 18-27.

Eglīte M., Aulika B., Avota M. Environmental health. 2008. Rīga Stradiņš University. Vides veselība. Rīgas Stradiņa universitāte. 2008. 696 lpp.

Medvedev M., Gorbovskij S. "Destroying of pathogenic mycrobes using laser berams", Bulletin about atomic energy, vol. 8, pp. 43-45, 2003. Медведев М., Горбовский С. 2003. Уничтожение патогенных микробов с помощью лазерного излучения. Бюллетень по атомной энергии, 8: 43-45.

Kasumyan A.S., Azoskova O.V. "Antibacterial effects of low-level laser radiationwith different wave length," Smolensk State Medical almanac, vol. 1 (1), pp. 31-33, 2015. Касумьян А.С., Азовскова О.В., Лелянов А.Д., Федосов Е.А. 2015. Антибактериальное действие низкоинтенсивного лазерного излучения с различной длиной волны. Смоленский медицинский альманах 1 ( 1 ): 31-33.

Hibst R., Graser R., Udart M., Stock K. "Mechanism of high-power NIR laser bacteria inactivation," Journal of Biophotonics, vol. 3 (5-6), pp. 296–303, 2010.



  • There are currently no refbacks.