Exploitation of Endemic Extremophilic Microbial Strains Isolated from Date Palm Fibrillium in the Saoura Region (Southwest Algeria) as Potential Biocontrol Agents against Mosquitoes
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Abstract
Background: Algeria’s extreme ecosystems, such as the Saoura region, represent unique reservoirs of rare microorganisms, inhabiting pristine and unexplored virgin territories with considerable biotechnological potential. Chitinolytic bacteria are particularly noteworthy for mosquito control due to their ability to degrade chitin, the major structural component of the insect cuticle. This study aims to: (i) identify new microbial strains adapted to extreme desert conditions, overcoming the limited efficacy of some bioinsecticides, (ii) address the spread of vector-borne diseases and mosquito resistance, (iii) reduce the environmental impacts of non-selective insecticides, and (iv) explore eco-friendly strategies and integrated biological control.
Methods: Shrimp chitin was extracted to prepare selective media for the isolation and purification of chitinolytic bacteria. The entomopathogenic activity of these chitinolytic strains at concentrations of 10⁴, 10⁵ and 10⁶ CFU/mL was evaluated through bioassays on Culex pipiens larvae.
Results: We isolated three chitinolytic strains from Phoenix dactylifera bark, among which Streptomyces spp. 2 (STR2) was clearly the most virulent against Cx. pipiens larvae. This strain exhibited marked dose and time-dependent toxicity (LC50-LC99: 7.9×10³-3.4×10⁷ CFU/mL; DC: 6.8×10⁷ CFU/mL; LT50: 4.6 days). Beyond larval mortality, it also severely affected adults by reducing the proportion of flight-capable mosquitoes and increasing rates of flightlessness, post-emergence mortality, and deformity. However, an IGR-like mode of action remains speculative.
Conclusion: This study confirms the larvicidal activity of desert-adapted chitinolytic bacteria, but further research is needed to determine their selectivity toward non-target organisms before considering their application in mosquito management.
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2. World Health Organization (WHO) (2022) World malaria report 2022. World Health Organization, Geneva. Available at: https://www.who.int/publications/i/item/978924006489.
3. Sharma A, Singh P, Gupta R (2022) Acti-nomycetes as potential biocontrol agents: chitinase-mediated insecticidal activity. J Appl Microbiol. 132(2): 789–802.
4. Ghosh A, Chandra G, Sahu SK (2023) Sus¬tainable strategies for mosquito control: biological approaches. Acta Trop. 246: 106–115.
5. Munyakanage D, Niyituma E, Mutabazi A, Misago X, Musanabaganwa C, Remera E, Rutayisire E, Ingabire MM, Majam¬bere S, Mbituyumuremyi A, Ngugi MP, Kokwaro E, Hakizimana E, Muvunyi CM (2024) The impact of Bacillus thu¬ringiensis var. israelensis (Vectobac® WDG) larvicide sprayed with drones on the bio-control of ma-laria vectors in rice fields of sub-urban Kigali, Rwanda. Ma¬lar J. 23(1): 281.
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7. Surya W, Chooduang S, Choong YK, Torres J, Boonserm P (2016) Binary toxin sub¬units of Lysinibacillus sphaer-icus are monomeric and form hetero-dimers af¬ter in vitro activation. PLoS One. 11 (6): e0158356.
8. Hegazy MI, Hegazy AM, Saad AM, Sa-lem HM, El-Tahan AM, El-Saadony MT, Soliman SM, Taha AE, Alshehri MA, Ahmed AE, Swelum AA (2022) Some biologically active microorgan-isms have the potential to suppress mos¬quito larvae (Culex pipiens, Dip-tera: Cu¬licidae). Saudi J Biol Sci. 29(4): 1998–2006.
9. Zogo B, N’Cho Tchiekoi B, Koffi AA, Dahounto A, Ahoua Alou LP, Dabiré RK, Baba-Moussa L, Moiroux N (2019) Impact of sunlight exposure on the re¬sidual efficacy of biolarvicides Bacillus thuringiensis israelensis and Bacillus sphaer¬icus against the main malaria vec¬tor, Anopheles gambiae. Malar J. 18: 55.
10. Hasan S, Boddu VM, Viswanath DS, Ghosh TK (2022) Preparation of chitin and chitosan. In: Chitin and Chitosan: Science and Engineering. Springer In-ternational Publishing, Cham, pp. 17–50.
11. El-araby A, El Ghadraoui L, Errachidi F (2022) Physicochemical properties and functional characteristics of ecological-ly extracted shrimp chitosans with dif-ferent organic acids during deminerali-zation step. Molecules. 27(23): 8285.
12. Tiwari D, Shouche S, Bhati P, Das P (2021) A consolidated method for se-lective isolation of actinomycetes based on choice of substrate. Int Ann Sci. 11 (1): 10–21.
13. Alvarenga VO, Campagnollo FB, Silva RA, Hubinger MD, Lang É, Amorim-Neto DP, Sant’Ana AS (2025) Impact of sublethal treatments on dormant and non-dormant populations of Bacillus ce¬reus spores during spray drying and on their recovery during whole milk powder storage. Int Dairy J. 165: 106208.
14. Wen J, Smelt JPPM, Vischer NOE, de Vos AL, Setlow P, Brul S (2022) Heat activation and inactivation of bacterial spores: is there an overlap? Appl Envi-ron Microbiol. 88(5): e02324.
15. Reva ON, Sorokulova IB, Smirnov VV (2001) Simplified technique for identi-fication of the aerobic spore-forming bacteria by phenotype. Int J Syst Evol Microbiol. 51(4): 1361–1371.
16. Wildermuth H (1972) Morphological sur-face characteristics of Streptomyces glau¬cescens and S. acrimycini, two strep¬to¬mycetes with ‘hairy’ spores. Arch Mi¬crobiol. 81(4): 321–332.
17. Hellany H, Assaf JC, Matta J, Khalil MI (2024) Fungal isolation, detection, and quantification of aflatoxins in nuts sold in the Lebanese market. Processes. 12 (5): 1018.
18. Komaki H (2023) Recent progress of re-classification of the genus Strepto-myces. Microorganisms. 11(4): 831.
19. Xu X, Kovács ÁT (2024) How to identi-fy and quantify the members of the Ba-cillus genus? Environ Microbiol. 26(2): e16593.
20. Alnahari AA, Kusa AM, Al Ghamdi AK, Algashgari B, Alqurashi SI, Mahyoub JA, Baeshen MN (2025) Evaluating bi-oassay efficacy of extremophile Bacil-lus species for environmentally safe con¬trol of Aedes aegypti larvae. Sci Rep. 15: 24469.
21. Seratnahaei M, Zahraei-Ramazani A, Eshraghi SS, Yaseri M, Pakzad P (2023) Larvicidal effects of metabolites ex¬tracted from Nocardia and Strepto-my¬ces species against the fourth larval stage of Anopheles stephensi (Diptera: Cu¬licidae). J Arthropod Borne Dis. 17(2): 187–196.
22. Rajchanuwong P, Peaboon S, Ngoen-Klan R, Rattanawannee A, Noosidum A, Promdon¬koy B, Chanpaisaeng J, Chareonviri¬yaphap T (2025) Larvicidal activity of Bacillus thuringiensis strains against Aedes aegypti and Culex quin-quefasciatus mosquitoes. Curr Res Par-asitol Vector Borne Dis. 7: 100245.
23. Ahmed M, Hassan R, El-Sayed A (2022) Biological control of Aedes aegypti mos¬quitoes using Bacillus thurin¬giensis. Egypt J Biol Sci For. 10(3): 45–55.
24. Li Q, Zhang X, Zhao Y (2023) New na-tive Bacillus thuringiensis strains in-duce high insecticidal action against Culex pipiens pallens larvae and adults. BMC Microbiol. 23: 100, 1–14.
25. Pochon J, Tardieux P (1962) Techniques d’analyse en microbiologie du sol [Tech¬niques of analysis in soil micro-biolo¬gy]. Éditions de la Tourelle, Saint-Man¬dé, France.
26. Younes I, Rinaudo M (2015) Chitin and chitosan preparation from marine sources: structure, properties and ap-plications. Mar Drugs. 13(3): 1133–1174.
27. Paul MK, Mathew J (2023) Mosquito larvicidal activity of chitinase of Pseu-domonas putida Mb 12 against the hu-man vector Aedes aegypti. J Pure Appl Microbiol. 17(1): 403–410.
28. Barka EA, Vatsa P, Sanchez L, Gaveau-Vaillant N, Jacquard C, Klenk HP, Clément C, Ouhdouch Y, Van Wezel GP (2016) Taxonomy, physiology, and natural products of actinobacteria. Mi-crobiol Mol Biol Rev. 80(1): 1–43.
29. Ganesan P, Anand S, Sivanandhan S, David RHA, Paulraj MG, Abdullah N, Ignacimuthu S (2018) Larvicidal, ovi-cidal and repellent activities of Strep-tomyces enissocaesilis (S12–17) isolat-ed from the Western Ghats of Tamil Nadu, India. J Entomol Zool Stud. 6 (2): 1828–1835.
30. Amelia-Yap ZH, Low VL, Saeung A, Ng FL, Chen CD, Hassandarvish P, Tan GYA, AbuBakar S, Azman AS (2023) Insecticidal activities of Streptomyces sp. KSF103 ethyl acetate extract against medically important mosqui¬toes and non-target organisms. Sci Rep. 13(1): 4.
31. Sharif MA, Raza FA, Sajid I (2024) Eval¬uation of larvicidal potential of Strep¬tomyces extracts against Aedes aegypti. J Microbiol Mol Genet. 5(3): 189–203.
32. Silva-Filha MHNL, Romão TP, Rezende TMT, Carvalho KdS, Gouveia de Menezes HS, Alexandre do Nascimen-to N, Soberón M, Bravo A (2021) Bac-terial toxins active against mosquitoes: mode of action and resistance. Toxins. 13(8): 523.
33. World Health Organization (2005) Guide¬lines for laboratory and field test¬ing of mosquito larvicides (WHO/CDS/WHOPES/GCDPP/2005.13). World Health Organization, Gene-va.
34. Lima EP, Goulart MOF, Rolim Neto ML (2015) Meta-analysis of studies on chem¬ical, physical and biological agents in the control of Aedes aegypti. BMC Public Health. 15: 858.
35. De Souza Wuillda ACJ, Campos Martins RC, Costa FDN (2019) Larvicidal ac-tivity of secondary plant metabolites in Aedes aegypti control: an overview of the previous 6 years. Nat Prod Com-mun. 14(7): 1934578X19862893.
36. Suman DS, Wang Y, Bilgrami AL, Gaugler R (2013) Ovicidal activity of three in¬sect growth regulators against Aedes and Culex mosquitoes. Acta Trop. 128(1): 103–109.
37. Bull AT, Asenjo JA (2013) Microbiolo¬gy of hyper-arid environments: recent insights from the Atacama Desert, Chile. Antonie Van Leeuwenhoek. 103(6): 1173–1179.
2. World Health Organization (WHO) (2022) World malaria report 2022. World Health Organization, Geneva. Available at: https://www.who.int/publications/i/item/978924006489.
3. Sharma A, Singh P, Gupta R (2022) Acti-nomycetes as potential biocontrol agents: chitinase-mediated insecticidal activity. J Appl Microbiol. 132(2): 789–802.
4. Ghosh A, Chandra G, Sahu SK (2023) Sus¬tainable strategies for mosquito control: biological approaches. Acta Trop. 246: 106–115.
5. Munyakanage D, Niyituma E, Mutabazi A, Misago X, Musanabaganwa C, Remera E, Rutayisire E, Ingabire MM, Majam¬bere S, Mbituyumuremyi A, Ngugi MP, Kokwaro E, Hakizimana E, Muvunyi CM (2024) The impact of Bacillus thu¬ringiensis var. israelensis (Vectobac® WDG) larvicide sprayed with drones on the bio-control of ma-laria vectors in rice fields of sub-urban Kigali, Rwanda. Ma¬lar J. 23(1): 281.
6. Van Nieuwpoort JC, Schrama M, Spitzen J, Boerlijst SP (2025) Beyond the tar-get insects: impacts of Bti on aquatic macrofauna communities. Parasit Vec-tors. 18(271): 1–8.
7. Surya W, Chooduang S, Choong YK, Torres J, Boonserm P (2016) Binary toxin sub¬units of Lysinibacillus sphaer-icus are monomeric and form hetero-dimers af¬ter in vitro activation. PLoS One. 11 (6): e0158356.
8. Hegazy MI, Hegazy AM, Saad AM, Sa-lem HM, El-Tahan AM, El-Saadony MT, Soliman SM, Taha AE, Alshehri MA, Ahmed AE, Swelum AA (2022) Some biologically active microorgan-isms have the potential to suppress mos¬quito larvae (Culex pipiens, Dip-tera: Cu¬licidae). Saudi J Biol Sci. 29(4): 1998–2006.
9. Zogo B, N’Cho Tchiekoi B, Koffi AA, Dahounto A, Ahoua Alou LP, Dabiré RK, Baba-Moussa L, Moiroux N (2019) Impact of sunlight exposure on the re¬sidual efficacy of biolarvicides Bacillus thuringiensis israelensis and Bacillus sphaer¬icus against the main malaria vec¬tor, Anopheles gambiae. Malar J. 18: 55.
10. Hasan S, Boddu VM, Viswanath DS, Ghosh TK (2022) Preparation of chitin and chitosan. In: Chitin and Chitosan: Science and Engineering. Springer In-ternational Publishing, Cham, pp. 17–50.
11. El-araby A, El Ghadraoui L, Errachidi F (2022) Physicochemical properties and functional characteristics of ecological-ly extracted shrimp chitosans with dif-ferent organic acids during deminerali-zation step. Molecules. 27(23): 8285.
12. Tiwari D, Shouche S, Bhati P, Das P (2021) A consolidated method for se-lective isolation of actinomycetes based on choice of substrate. Int Ann Sci. 11 (1): 10–21.
13. Alvarenga VO, Campagnollo FB, Silva RA, Hubinger MD, Lang É, Amorim-Neto DP, Sant’Ana AS (2025) Impact of sublethal treatments on dormant and non-dormant populations of Bacillus ce¬reus spores during spray drying and on their recovery during whole milk powder storage. Int Dairy J. 165: 106208.
14. Wen J, Smelt JPPM, Vischer NOE, de Vos AL, Setlow P, Brul S (2022) Heat activation and inactivation of bacterial spores: is there an overlap? Appl Envi-ron Microbiol. 88(5): e02324.
15. Reva ON, Sorokulova IB, Smirnov VV (2001) Simplified technique for identi-fication of the aerobic spore-forming bacteria by phenotype. Int J Syst Evol Microbiol. 51(4): 1361–1371.
16. Wildermuth H (1972) Morphological sur-face characteristics of Streptomyces glau¬cescens and S. acrimycini, two strep¬to¬mycetes with ‘hairy’ spores. Arch Mi¬crobiol. 81(4): 321–332.
17. Hellany H, Assaf JC, Matta J, Khalil MI (2024) Fungal isolation, detection, and quantification of aflatoxins in nuts sold in the Lebanese market. Processes. 12 (5): 1018.
18. Komaki H (2023) Recent progress of re-classification of the genus Strepto-myces. Microorganisms. 11(4): 831.
19. Xu X, Kovács ÁT (2024) How to identi-fy and quantify the members of the Ba-cillus genus? Environ Microbiol. 26(2): e16593.
20. Alnahari AA, Kusa AM, Al Ghamdi AK, Algashgari B, Alqurashi SI, Mahyoub JA, Baeshen MN (2025) Evaluating bi-oassay efficacy of extremophile Bacil-lus species for environmentally safe con¬trol of Aedes aegypti larvae. Sci Rep. 15: 24469.
21. Seratnahaei M, Zahraei-Ramazani A, Eshraghi SS, Yaseri M, Pakzad P (2023) Larvicidal effects of metabolites ex¬tracted from Nocardia and Strepto-my¬ces species against the fourth larval stage of Anopheles stephensi (Diptera: Cu¬licidae). J Arthropod Borne Dis. 17(2): 187–196.
22. Rajchanuwong P, Peaboon S, Ngoen-Klan R, Rattanawannee A, Noosidum A, Promdon¬koy B, Chanpaisaeng J, Chareonviri¬yaphap T (2025) Larvicidal activity of Bacillus thuringiensis strains against Aedes aegypti and Culex quin-quefasciatus mosquitoes. Curr Res Par-asitol Vector Borne Dis. 7: 100245.
23. Ahmed M, Hassan R, El-Sayed A (2022) Biological control of Aedes aegypti mos¬quitoes using Bacillus thurin¬giensis. Egypt J Biol Sci For. 10(3): 45–55.
24. Li Q, Zhang X, Zhao Y (2023) New na-tive Bacillus thuringiensis strains in-duce high insecticidal action against Culex pipiens pallens larvae and adults. BMC Microbiol. 23: 100, 1–14.
25. Pochon J, Tardieux P (1962) Techniques d’analyse en microbiologie du sol [Tech¬niques of analysis in soil micro-biolo¬gy]. Éditions de la Tourelle, Saint-Man¬dé, France.
26. Younes I, Rinaudo M (2015) Chitin and chitosan preparation from marine sources: structure, properties and ap-plications. Mar Drugs. 13(3): 1133–1174.
27. Paul MK, Mathew J (2023) Mosquito larvicidal activity of chitinase of Pseu-domonas putida Mb 12 against the hu-man vector Aedes aegypti. J Pure Appl Microbiol. 17(1): 403–410.
28. Barka EA, Vatsa P, Sanchez L, Gaveau-Vaillant N, Jacquard C, Klenk HP, Clément C, Ouhdouch Y, Van Wezel GP (2016) Taxonomy, physiology, and natural products of actinobacteria. Mi-crobiol Mol Biol Rev. 80(1): 1–43.
29. Ganesan P, Anand S, Sivanandhan S, David RHA, Paulraj MG, Abdullah N, Ignacimuthu S (2018) Larvicidal, ovi-cidal and repellent activities of Strep-tomyces enissocaesilis (S12–17) isolat-ed from the Western Ghats of Tamil Nadu, India. J Entomol Zool Stud. 6 (2): 1828–1835.
30. Amelia-Yap ZH, Low VL, Saeung A, Ng FL, Chen CD, Hassandarvish P, Tan GYA, AbuBakar S, Azman AS (2023) Insecticidal activities of Streptomyces sp. KSF103 ethyl acetate extract against medically important mosqui¬toes and non-target organisms. Sci Rep. 13(1): 4.
31. Sharif MA, Raza FA, Sajid I (2024) Eval¬uation of larvicidal potential of Strep¬tomyces extracts against Aedes aegypti. J Microbiol Mol Genet. 5(3): 189–203.
32. Silva-Filha MHNL, Romão TP, Rezende TMT, Carvalho KdS, Gouveia de Menezes HS, Alexandre do Nascimen-to N, Soberón M, Bravo A (2021) Bac-terial toxins active against mosquitoes: mode of action and resistance. Toxins. 13(8): 523.
33. World Health Organization (2005) Guide¬lines for laboratory and field test¬ing of mosquito larvicides (WHO/CDS/WHOPES/GCDPP/2005.13). World Health Organization, Gene-va.
34. Lima EP, Goulart MOF, Rolim Neto ML (2015) Meta-analysis of studies on chem¬ical, physical and biological agents in the control of Aedes aegypti. BMC Public Health. 15: 858.
35. De Souza Wuillda ACJ, Campos Martins RC, Costa FDN (2019) Larvicidal ac-tivity of secondary plant metabolites in Aedes aegypti control: an overview of the previous 6 years. Nat Prod Com-mun. 14(7): 1934578X19862893.
36. Suman DS, Wang Y, Bilgrami AL, Gaugler R (2013) Ovicidal activity of three in¬sect growth regulators against Aedes and Culex mosquitoes. Acta Trop. 128(1): 103–109.
37. Bull AT, Asenjo JA (2013) Microbiolo¬gy of hyper-arid environments: recent insights from the Atacama Desert, Chile. Antonie Van Leeuwenhoek. 103(6): 1173–1179.
| Files | ||
| Issue | Vol 19 No 3 (2025) | |
| Section | Original Article | |
| Keywords | ||
| Biological control Chitinolytic microorganisms Culex pipiens Phoenix dactylifera | ||
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How to Cite
1.
Ali B, Benlarbi L, Hamani Z. Exploitation of Endemic Extremophilic Microbial Strains Isolated from Date Palm Fibrillium in the Saoura Region (Southwest Algeria) as Potential Biocontrol Agents against Mosquitoes. J Arthropod Borne Dis. 2026;19(3):241–258.
