Analisis Efek Stres Oksidatif Dan Pelepasan Cu Dari Biokonjugasi Cu₂O–Xilanase–Bacillus Amyloliquefaciens Pada Aplikasi Nanobiofertilizer

Febriyanti, Thania (2026) Analisis Efek Stres Oksidatif Dan Pelepasan Cu Dari Biokonjugasi Cu₂O–Xilanase–Bacillus Amyloliquefaciens Pada Aplikasi Nanobiofertilizer. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Nanobiofertilizer berbasis Cu₂O dikembangkan untuk menyediakan Cu sebagai hara mikro dengan pelepasan terkendali sekaligus menekan stres oksidatif berlebih pada sistem tanah–tanaman. Penelitian ini mengevaluasi pelepasan Cu, pembentukan stres oksidatif, serta respons sifat kimia tanah dan pertumbuhan tanaman berbuah akibat aplikasi nanobiofertilizer hasil biokonjugasi Cu₂O–xilanase–Bacillus amyloliquefaciens (CuBA). Cu₂O quantum dots disintesis menggunakan metode hot-soap, dikonjugasikan dengan biomassa B. amyloliquefaciens, dan diformulasikan sebagai CuBA, kemudian dievaluasi melalui karakterisasi UV–Vis, estimasi ROS sebagai H₂O₂, analisis Cu tanah (ICP), sifat kimia tanah (pH dan electrical conductivity/EC), ketersediaan N, P, K dan indeks kesuburan tanah, serta respons vegetatif dan generatif tanaman. Karakterisasi UV–Vis menunjukkan bahwa Cu₂O quantum dots memiliki tepi serapan pada 506 nm dengan band gap 2,7 eV. Estimasi ROS menunjukkan bahwa Cu terlarut menghasilkan ROS sangat rendah (15,86–25,82 mg·L⁻¹ H₂O₂), sedangkan perlakuan biologis menghasilkan ROS moderat (BA =199,89; CuBA 12.5 = 188,50; CuBA 25 = 206,53 mg·L⁻¹), yang merepresentasikan stres oksidatif adaptif; konsentrasi Cu tanah setelah 7 hari tetap aman dan relatif seragam (9,99–11,71 mg·kg⁻¹). Pada tanah tanpa tanaman, nilai konstanta awal (y) N, P, K dan indeks kesuburan relatif tinggi, terutama pada CuBA 12.5 (257,18) dan CuBA 25 (242,75) akibat tidak terjadinya penyerapan. Pada tanaman sehat, nilai y NPK menurun sebagai indikasi penyerapan aktif, dengan CuBA 12.5 menunjukkan ketersediaan NPK paling efisien (N = 23,18; P = 32,20; K = 74,36 mg·kg⁻¹), disertai pH agronomis (5,2–5,6) dan EC non-salin (<400 µS·cm⁻¹). Sebaliknya, pada tanaman sakit, nilai y NPK dan indeks kesuburan relatif lebih tinggi pada CuBA 25 (N =21,65; P =30,33; K =70,40 mg·kg⁻¹; fertility = 242,75) dengan R² lebih besar, menunjukkan ketersediaan hara yang tidak diikuti penyerapan optimal. Secara morfologi, fase vegetatif paling stabil ditunjukkan oleh CuBA 12.5, ditandai oleh tinggi tanaman yang lebih seragam, daun rontok lebih rendah, dan R² pertumbuhan vegetatif rendah (0,12–0,30), sedangkan fase generatif terbaik ditunjukkan oleh CuBA 25, dengan pembungaan dan pembesaran buah paling stabil serta diameter buah rata-rata 2,2–2,4 cm. Secara keseluruhan, CuBA 12.5 unggul pada fase vegetatif melalui efisiensi penyerapan NPK, sedangkan CuBA 25 unggul pada fase generatif, menunjukkan bahwa perbedaan konsentrasi CuBA menentukan dominansi respons tanaman pada tiap fase pertumbuhan.
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Cu₂O-based nanobiofertilizers are developed to supply copper (Cu) as an essential micronutrient through controlled release while minimizing excessive oxidative stress in soil–plant systems. This study evaluates Cu release, oxidative stress formation, soil chemical responses, and growth of fruit-bearing plants following application of a nanobiofertilizer derived from the bioconjugation of Cu₂O–xylanase–Bacillus amyloliquefaciens (CuBA). Cu₂O quantum dots were synthesized via a hot-soap method, bioconjugated with B. amyloliquefaciens biomass, and formulated as CuBA. Evaluation included UV–Vis characterization, ROS estimation as H₂O₂, soil Cu analysis (ICP), soil chemical properties (pH and electrical conductivity/EC), macronutrient availability (N, P, K) and fertility index, as well as vegetative and generative plant responses. UV–Vis analysis showed that the synthesized Cu₂O quantum dots exhibited an absorption edge at 506 nm, corresponding to a band gap of 2.7 eV. Dissolved Cu produced very low ROS levels (15.86–25.82 mg·L⁻¹ H₂O₂), whereas biologically amended treatments generated moderate ROS (BA =199.89; CuBA 12.5 =188.50; CuBA 25 =206.53 mg·L⁻¹), representing adaptive oxidative stress; soil Cu concentrations after 7 days remained safe and uniform (9.99–11.71 mg·kg⁻¹). Under soil-only conditions, the initial constant (y) values of N, P, K and the fertility index were relatively high, particularly for CuBA 12.5 (257.18) and CuBA 25 (242.75), due to the absence of plant uptake. In healthy plants, y values decreased, indicating active nutrient uptake, with CuBA 12.5 showing the most efficient NPK availability (N =23.18; P =32.20; K =74.36 mg·kg⁻¹), accompanied by agronomic pH (5.2–5.6) and non-saline EC (<400 µS·cm⁻¹). Conversely, in stressed plants, higher y and fertility values particularly for CuBA 25 (N =21.65; P =30.33; K =70.40 mg·kg⁻¹; fertility =242.75) with higher R² indicated nutrient accumulation in soil due to suboptimal uptake. Morphologically, the most stable vegetative growth occurred with CuBA 12.5, characterized by more uniform plant height, lower leaf abscission, and low vegetative R² values (0.12–0.30). In contrast, the best generative performance was achieved with CuBA 25, showing the most consistent flowering and fruit development, with an average fruit diameter of 2.2–2.4 cm. Overall, CuBA 12.5 is optimal for vegetative growth through efficient NPK uptake, whereas CuBA 25 is optimal for the generative phase, demonstrating that CuBA concentration governs phase-specific plant responses.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	nanobiofertilizer, Cu₂O, Bacillus amyloliquefaciens, xilanase, stres oksidatif, NPK, nanobiofertilizer, Cu₂O, Bacillus amyloliquefaciens, xylanase, oxidative stress, NPK.
Subjects:	Q Science > QK Botany > QK710 Plant physiology Q Science > QR Microbiology > QR74.8 Bacteria S Agriculture > S Agriculture (General) > S633.5 Fertilizers S Agriculture > S Agriculture (General) > S654.5 Biofertilizers T Technology > TP Chemical technology > TP248 Nanogels. Nanoparticles. T Technology > TP Chemical technology > TP248.27.P55 Plant biotechnology.
Divisions:	Faculty of Industrial Technology > Material & Metallurgical Engineering > 28201-(S1) Undergraduate Thesis
Depositing User:	Thania Febriyanti
Date Deposited:	26 Jan 2026 03:52
Last Modified:	26 Jan 2026 03:52
URI:	http://repository.its.ac.id/id/eprint/130110

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