Aplikasi Endospora Lysinibacillus fusiformis JH2 Dan Bacillus safensis IDN1 Untuk Meningkatkan Kepadatan Mortar Geopolymer

Azzura, Aurel Keiko (2026) Aplikasi Endospora Lysinibacillus fusiformis JH2 Dan Bacillus safensis IDN1 Untuk Meningkatkan Kepadatan Mortar Geopolymer. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Geopolimer berbasis fly ash dikembangkan sebagai material konstruksi ramah lingkungan, namun mortar geopolimer masih rentan mengalami mikroretak dan patah rapuh. Aplikasi endospora bakteri menjadi pendekatan bioteknologi yang berpotensi meningkatkan sifat mekanik dan karakteristik porositas karena mampu bertahan pada lingkungan alkali. Penelitian ini bertujuan menganalisis pengaruh aplikasi endospora Lysinibacillus fusiformis JH2 dan Bacillus safensis IDN1 terhadap kuat tekan, kuat tarik belah, porositas, dan viabilitas mortar geopolimer. Endospora diproduksi menggunakan media YU broth, dipanen menjadi endospora kering, kemudian diaplikasikan ke dalam mortar. Pengujian kuat tekan (ASTM C39/C39M) dan porositas (ASTM C642) dilakukan pada umur curing 7 dan 28 hari, sedangkan kuat tarik belah (ASTM C496/C496M) diuji pada umur curing 28 hari. Viabilitas endospora dievaluasi melalui perhitungan colony forming unit (CFU). Hasil penelitian menunjukkan bahwa aplikasi endospora meningkatkan kuat tekan mortar geopolimer pada umur curing 7 hari, dengan nilai tertinggi diperoleh pada perlakuan B. safensis IDN1 sebesar 15,26 MPa pada NaOH 8 M, sedangkan pada umur curing 28 hari, nilai tertinggi diperoleh pada perlakuan B. safensis IDN1 sebesar 36.74 MPa. Konsentrasi NaOH menjadi faktor utama pembentuk kuat tekan, namun endospora meningkatkan performa mortar pada NaOH 4 M hingga setara atau melebihi kontrol 8 M. Aplikasi endospora juga meningkatkan kuat tarik belah dibandingkan kontrol serta cenderung menurunkan porositas terbuka yang diikuti peningkatan porositas tertutup. Endospora L. fusiformis JH2 dan B. safensis tetap viabel setelah diaplikasikan ke dalam mortar geopolimer, dengan B. safensis IDN1 memiliki viabilitas lebih tinggi.
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Fly ash-based geopolymers have been developed as environmentally friendly construction materials. However, geopolymer mortar remains susceptible to microcracking and brittle failure. Bacterial endospores offer a biotechnological approach to improve the mechanical properties and porosity characteristics of geopolymer mortar due to their ability to survive in highly alkaline environments. This study investigated the effects of Lysinibacillus fusiformis JH2 and Bacillus safensis IDN1 endospores on the compressive strength, splitting tensile strength, porosity, and viability of geopolymer mortar. Dry endospores produced in YU broth were incorporated into the mortar mixture. Compressive strength (ASTM C39/C39M) and porosity (ASTM C642) were evaluated after 7 and 28 days of curing, while splitting tensile strength (ASTM C496/C496M) was measured after 28 days. Endospore viability was determined by colony-forming unit (CFU) enumeration. Endospore application increased the compressive strength of geopolymer mortar, with the highest values of 15.26 MPa at 7 days and 36.74 MPa at 28 days obtained for B. safensis IDN1 at 8 M NaOH. Although NaOH concentration was the primary factor governing compressive strength, endospore application improved the performance of 4 M NaOH mortar to levels comparable to or higher than the 8 M control. Endospore application also enhanced splitting tensile strength, reduced open porosity while increasing closed porosity, and maintained the viability of both L. fusiformis JH2 and B. safensis, with B. safensis IDN1 exhibiting higher viability.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Mortar Geopolimer, Endospora, Lysinibacillus fusiformis JH2, Bacillus safensis IDN1, Viabilitas. ======================================================================================================================== Geopolymer Mortar, Endospore, Lysinibacillus fusiformis JH2, Bacillus safensis IDN1, Viability.
Subjects:	Q Science Q Science > QR Microbiology Q Science > QR Microbiology > QR74.8 Bacteria
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Biology > 46201-(S1) Undergraduate Thesis
Depositing User:	Aurel Keiko Azzura
Date Deposited:	01 Aug 2026 05:02
Last Modified:	01 Aug 2026 05:02
URI:	http://repository.its.ac.id/id/eprint/141659

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