Diversity and Abundance of Some Microbial Communities in Kenya's Rift Valley Lakes Nakuru and Bogoria Before the 2019-2020 Long Rains

Domitila Kyule^1, , Nicholas Outa², Jacob Iteba³, Erick Ogello², Jonathan Munguti¹, Kevin Obiero⁴, Elick Otachi⁵ and Anastasia Muia⁵

¹Kenya Marine and Fisheries Research Institute (KMFRI), National Aquaculture Research Development and Training Center (NARDTC), P. O. Box 451, Sagana, Kenya

²Department of Animal and Fisheries Sciences, Maseno University, P.O. Box Private Bag, Maseno

³Directorate of Fisheries, County Government of Busia, P.O Box 142, Busia, Kenya

⁴Kenya Marine & Fisheries Research Institute, Sangoro Aquaculture Research Station, Pap-Onditi, Kenya

⁵Department of Biological Sciences, Egerton University, Njoro, Kenya

Cite this paper:
Domitila Kyule, Nicholas Outa, Jacob Iteba, Erick Ogello, Jonathan Munguti, Kevin Obiero, Elick Otachi and Anastasia Muia. Diversity and Abundance of Some Microbial Communities in Kenya's Rift Valley Lakes Nakuru and Bogoria Before the 2019-2020 Long Rains. Journal of Aquatic Science. 2024; 7(1):9-18. doi: 10.12691/jas-7-1-2

Abstract

The recent heavy rains in many parts of Kenya have changed several aspects of the Rift Valley lakes. Data collected before the rainfall events is therefore crucial for a better understanding of these systems hence the need for this paper. Two Rift Valley lakes in Kenya (Nakuru and Bogoria) were investigated between June 2008 and January 2009. The objective of the study was to investigate the dynamics and abundances of viruses, heterotrophic bacteria and phytoplankton biomass. Three sampling sites were selected in both Lakes. Temperature and conductivity were determined by probes in situ while Soluble Reactive Phosphorous (SRP) was determined using the ascorbic acid method. Dissolved Organic Carbon (DOC) was measured as non-purgeable organic carbon with a TOC-VCPH total organic carbon analyzer, while chl-a was extracted with acetone. Water samples for bacterio- virioplankton were fixed immediately after collection and enumeration of samples stained with SYBR Gold was done with epifluorescence microscopy. It was observed that conductivity was twice higher in Lake Bogoria than in Nakuru, and higher temperatures were recorded in the former than in the latter. DOC in Lake Nakuru was three times higher than that of Bogoria. Chl-a and SRP exhibited an antagonistic interrelationship. Virus abundances in Lake Nakuru ranged from 0.51-141.6 ×108 ml-1, among the highest observed in any natural aquatic system examined so far, and for Lake Bogoria the range was between 0.17-15.0 ×108 ml-1. The numbers of heterotrophic bacteria were one order of magnitude lower than that of viruses and virus to bacteria ratio (VBR) in both lakes. The study revealed that temperature and conductivity have effects on bacterial, viral numbers and phytoplankton, that cyanophages appear to play an important role in the dynamics of phytoplankton. Further, molecular and genetics studies could help to elucidate the interplay among microorganisms. Publishing this study now can provide valuable information for understanding the long-term dynamics of the microbial communities in these lakes and how they may be affected by changes in precipitation, which can inform conservation and management efforts in Kenya.

Keywords:
Bacterioplakton viroplankton saline lakes lake Nakuru lake Bogoria

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Figures

References:

[1]	Andrews, J. H. (1976). The pathology of marine algae. Biol. Rev. 51: 211-253.
[2]	Fuhrman, J. A, Noble R. T (1995) Viruses and protists cause similar Bacterial mortality in coastal seawater. Limnol. Oceanogr. 40:1236–1242.
[3]	Vareschi, E., J. M. Melack, and P. Kilham, (1981). Saline waters. In: Symoens J. J., M. J. Burgis and J. J. Gaudet (Eds). The ecology and utilization of African inland waters. UNEP Reports Proc. Ser. 1, Nairobi: 93-102.
[4]	Talling, J. F., (2001). Environmental controls on the functioning of shallow tropical lakes. Hydrobiologia 458: 1-8.
[5]	Vareschi, E., (1987). Saline lake ecosystems in Schulze, E. D. and H. Zwo¨ lfer (eds). Potentials and Limitations of Ecosystem Analysis. Springer-Verlag Publishers, Berlin, 435 pp.
[6]	Oduor, S. O., M. Schagerl, (2007). Phytoplankton photosynthetic characteristics in three Kenyan Rift Valley saline-alkaline lakes. J. Plankton Res. 29(12):1041- 1050. of the East Sea, Korea. Aquat. Microb. Ecol. 30:1–9.
[7]	Owino, A. O., J.O. Oyugi, O.O. Nasirwa and L. A. Bennun, (2001). Patterns of variation in waterbird numbers on four Rift Valley lakes in Kenya, 1991-1999. Hydrobiologia 458: 45-53.
[8]	Oduor, S. O., M. Schagerl , (2007). Temporal Trends of ions and Nutrients in three Kenyan Rift Valley Saline-Alkaline Lakes and their influence on Phytoplankton biomass. Hydrobiologia 584:59-68.
[9]	APHA, (1995). Standard methods for the Examination of Water and Wastewater. American Public Health Association, Washington D. C., U. S. A., 20th Edition.
[10]	Tuma R. S, Beaudet M. P, Jim X. Jones L. J, Cheung C, Yue S. V, and Singer L. (1999) Characterization of SYBR Gold nucleic acid gel stain: a dye optimized for use with 300-nm ultraviolet transilluminators. Anal. Biochem. 268:278–288.
[11]	Elizabeth, Kebede, Zinabu-Gebre-Mariam and Ahlgren, I. (1994). Ethiopian Rift Valley lakes: chemical characteristics of a salinity alkalinity series. Hydrobiologia 288:1-12.
[12]	G. M. Zinabu, and W. D. Taylor. (1997). Bacteria-Chlorophyll a relationships in Ethiopian Lakes of varying salinity: are soda lakes different? J. Plankton Res. Vol.19 no.5 pp.647-654.
[13]	Jiang, S., G. Steward, R. Jellison, W. Chu and S. Choi, (2004). Abundance, Distribution and Diversity of Viruses in Alkaline, Hypersaline, Mono Lake, California. Microbial Ecol. 47: 9-17.
[14]	Yasindi, A. W., D. H. Lynn and W. D. Taylor, (2002). Ciliated protozoa in Lake Nakuru, a shallow alkaline-saline lake in Kenya: Seasonal variation, potential production and role in the food web. Arch. Hydrobiol. 154: 311-325.
[15]	Peduzzi, P. and F. Schiemer, (2004). Bacteria and viruses in the water column of tropical freshwater reservoirs. Environm. Microbiol. 6: 707-715.
[16]	Jiang, S. C., and J. H. Paul. (1994). Seasonal and diel abundance of viruses and occurrence of lysogeny/bacteriocinogeny in the marine environment. Mar. Ecol. Prog. Ser. 104:163–172.
[17]	Tuite, C. H. (1979). Population size, distribution and biomass density of the Lesser Flamingo in the Eastern Rift Valley, 1974-76. Journal of Applied Ecology, 765-775.
[18]	Bottrell, H.H., Duncan, A., Gliwicz, Z.M., Grygierek, E., Herzig, A., Hillbricht-Ilkowska, A., Kurosawa, H., Larsson, P. and Weglenska, T. (1976). A review of some problems in zooplankton production studies. Norw. J. Zool., 24:419-456.
[19]	Talling, J. F., & Lemoalle, J. (1998). Ecological dynamics of tropical inland waters. Cambridge University Press.
[20]	Guixa-Boixareu, N., Calderón-Paz, J. I., Heldal, M., Bratbak, G., & Pedrós-Alió, C. (1996). Viral lysis and bacterivory as prokaryotic loss factors along a salinity gradient. Aquatic Microbial Ecology, 11(3), 215-227.
[21]	Maranger, R., & Bird, D. F. (1995). Viral abundance in aquatic systems: a comparison between marine and fresh waters. Marine Ecology Progress Series, 121, 217-226.
[22]	Laybourn‐Parry, J., Hofer, J. S., & Sommaruga, R. (2001). Viruses in the plankton of freshwater and saline Antarctic lakes. Freshwater Biology, 46(9), 1279-1287.
[23]	Wommack, K. E., & Colwell, R. R. (2000). Virioplankton: viruses in aquatic ecosystems. Microbiology and molecular biology reviews, 64(1), 69-114.
[24]	Kirschner, A. K. T., Eiler, A., Zechmeister, T. C., Velimirov, B., Herzig, A., Mach, R., & Farnleitner, A. H. (2002). Extremely productive microbial communities in shallow saline pools respond immediately to changing meteorological conditions. Environmental microbiology, 4(9), 546-555.
[25]	Maranger, R., Bird, D. F., & Juniper, S. K. (1994). Viral and bacterial dynamics in Arctic sea ice during the spring algal bloom near Resolute, NWT, Canada. Marine Ecology Progress Series, 121-127.
[26]	Tuomi, P., Fagerbakke, K. M., Bratbak, G., & Heldal, M. (1995). Nutritional enrichment of a microbial community: the effects on activity, elemental composition, community structure and virus production. FEMS microbiology ecology, 16(2), 123-134.