A sustainable and effective bioprocessing approach for improvement of acid phosphatase production and rock phosphate solubilization by Bacillus haynesii strain ACP1

Abstract

There is indeed a tremendous increase in biotechnological production on a global scale, more and more innovative bioprocesses, therefore, require to perform ideally not only in a small lab- but also on large production scales. Efficient microbial process optimization is a significant challenge when accomplishing a variety of sustainable development and bioengineering application objectives. In Egypt's mines, several distinct types of rock phosphate (RP) are utilized as a source of phosphate fertilizers in agriculture. It is more ecologically beneficial to utilize RP bio-solubilization than acidulation. Therefore, this work aimed to strategically scale up the acid phosphatase (ACP) production and RP bio-solubilization by the newly-discovered Bacillus haynesii. The use of consecutive statistical experimental approaches of Plackett–Burman Design (PBD), and Rotatable Central Composite Design (RCCD), followed by pH-uncontrolled cultivation conditions in a 7 L bench-top bioreactor revealed an innovative medium formulation. These approaches substantially improved ACP production, reaching 207.6 U L−1 with an ACP yield coefficient Yp/x of 25.2 and a specific growth rate (µ) of 0.07 h−1. The metals Na, Li, and Mn were the most efficiently released from RP during the solubilization process by B. haynesii. The uncontrolled pH culture condition is the most suitable setting for simultaneously improving the ACP and organic acids production. The most abundant organic acid produced through the cultivation process was lactic acid, followed by glutamic acid and hydroxybenzoic acid isomer. The findings of TGA, DSC, SEM, EDS, FTIR, and XRD analysis emphasize the significant influence of organic acids and ACP activity on the solubilization of RP particles.

Eggshell waste bioprocessing for sustainable acid phosphatase production and minimizing environmental hazards

“…Additionally, the findings from the current investigation indicated that the activated pre-cultures were held at 5% (v/v) inoculum size to produce the most incredible ACP output (41.8 U L −1 ). The ACP production of the B. haynesii strain was found to be maximum at 4.0% (v/v) but reduced as the size of the inoculum rose, according to Abdelgalil et al's [ 13 ] study, which made the same discovery.…”

“…The results agreed with those obtained earlier by Musarrat et al [ 27 ], who discovered that the optimal pH range for bacteria to dissolve organic P ranged from neutral to moderately acidic. In addition, it was stated by Abdelgalil et al [ 13 ] that an ideal ACP activity peak of 49 U L −1 at pH 7.0 was noted; ACP throughput fell to 47.7 U L −1 at pH 8.0 beyond the optimum pH. Furthermore, the original pH unadjusted media (approximately pH 7.5) produced the most ACP (56.9 U L −1 ) in comparison to the changed media with 1 N HCl (49 U L −1 ) [ 13 ].…”

“…In addition, it was stated by Abdelgalil et al [ 13 ] that an ideal ACP activity peak of 49 U L −1 at pH 7.0 was noted; ACP throughput fell to 47.7 U L −1 at pH 8.0 beyond the optimum pH. Furthermore, the original pH unadjusted media (approximately pH 7.5) produced the most ACP (56.9 U L −1 ) in comparison to the changed media with 1 N HCl (49 U L −1 ) [ 13 ]. However, a finding that contradicts the present investigation was documented by Behera et al [ 28 ], who found that the most fabulous ACP production from Serratia sp.…”

“…Nonetheless, it was found that the B. haynesii strain ACP1 produced the most ACP (40.8 U L −1 ) at a temperature of 50 °C. [ 13 ].…”

“…The quantitative evaluation of ACP activity was carried out as described by Abdelgalil et al [ 13 ] The quantity of enzyme that generates 1.0 μmol ρ -nitrophenol in 1 min at pH 4.0 and 65 °C is given as an international unit (IU) and the activities were measured in U L −1 min −1 .…”