The study is to identify the extraction of intracellular inulinase (exo- and endoinulinase) and invertase as well as optimization medium composition for maximum productions of intra- and extracellular enzymes from Aspergillus niger ATCC 20611. From two different methods for extraction of intracellular enzymes, ultrasonic method was found more effective. Response surface methodology (RSM) with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. The effect of five main reaction parameters including sucrose, yeast extract, NaNO3, Zn+2, and Triton X-100 on the production of enzymes was analyzed. A modified quadratic model was fitted to the data with a coefficient of determination (R 2) more than 0.90 for all responses. The intra-extracellular inulinase and invertase productions increased in the range from 16 to 8.4 times in the optimized medium (10% (w/v) sucrose, 2.5% (w/v) yeast extract, 2% (w/v) NaNO3, 1.5 mM (v/v) Zn+2, and 1% (v/v) Triton X-100) by RSM and from around 1.2 to 1.3 times greater than in the medium optimized by one-factor-at-a-time, respectively. The results of bioprocesses optimization can be useful in the scale-up fermentation and food industry.

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The optimization of wheat starch esterification (acetylation) with a high degree of substitution was performed through response surface methodology (RSM) via various concentrations of reagents (acetic anhydride), pHs, and temperatures under various ultrasonication frequencies (25, 40, and 25 + 40 kHz). According to RSM methodology, optimized samples were selected by achieving high degrees of substitution at various frequencies, temperatures, and pHs. Solubility, swelling, X‐ray, RVA, DSC, freeze–thaw stability, texture, and SEM analysis of the optimized samples were performed at three frequencies. X‐ray pattern exhibited a more significant reduction in the crystallinity percentage of esterified starch at frequency 25 + 40 kHz compared with 25 kHz, 40 kHz, and native starch. According to DSC analysis, To, Tp, Tc, and enthalpy of gelatinization (ΔH gel) were lower in AC at frequency 25 + 40 kHz compared with AC at frequency 25 and 40 kHz and N starches. According to morphology analysis, in acetylated starches at 25 and 40 kHz, the surfaces and small granules underwent more damage, whereas in 25 + 40 kHz, large granules were more affected than small granules. Upon acetylation, freeze–thaw stability and textural properties of the starch significantly increased and decreased, respectively. The peak and final viscosity of acetylated starch increased (25 + 40 kHz ˃ 25 kHz ˃ 40 kHz ˃ N starch).

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Pramipexole drug was attached to the surface of multi-walled carbon nanotubes (MWCNTs) by reaction of acylated carbon nanotubes with pramipexole for the first time. The modified MWCNTs were characterized using Fourier transform infrared spectroscopy, transmission and scanning electron microscopies and CHNS analysis. The prepared pramipexole-MWCNTs were used for immobilization of palladium nanoparticles as a novel nanocatalyst. After characterization of the final nanocomposite, the pramipexole-MWCNTs/Pd was applied as a novel phosphinefree recyclable heterogeneous catalyst for Sonogashira reactions. Interestingly, the novel catalyst could be recovered and recycled five times without any significant loss in activity.KEYWORDS multi-walled carbon nanotubes, nanocatalyst, palladium, primapexole, Sonogashira | INTRODUCTIONSince their discovery by Iijima, [1] carbon nanotubes (CNTs) have attracted great interest in many fields of science and nanotechnology due to their fascinating and unique optical, electrical, mechanical, chemical and thermal properties. [2,3] The tubular structure of CNTs makes them unique among different forms of carbon, and they can thus be exploited as an alternative material for catalyst support in heterogeneous catalysis [4] and in fuel cells due to the large surface area-to-volume ratio, excellent electronic conductivity and high chemical stability. [5][6][7][8][9][10][11][12][13][14] Consequently, the exceptional properties of CNTs made them ideal candidates for numerous applications in nanoelectronics, [15][16][17][18] catalysis, [19][20][21][22][23][24][25] diagnostics [26,27] and drug delivery. [28,29] Wildgoose et al. reviewed the recent developments in this area by exploring the various techniques to functionalize CNTs with metals and other nanoparticles and the diverse applications of the resulting materials. [30] However, the applications of CNTs have been impeded by their poor solubility in solvents and polymers, which originates from strong van der Waals attractions among CNTs. Without surface modification, most CNTs lack sufficient binding sites for anchoring precursor metal ions or metal nanoparticles, which usually leads to poor dispersion and aggregation of metal nanoparticles, especially at high loading conditions. Therefore, functionalization of CNTs is generally a prerequisite to further applications. According to the nature of the interaction between CNTs and functional groups, the functionalization of CNTs can be categorized into covalent and non-covalent functionalization.The immobilization methods used to deposit palladium into heterogeneous solid beds have been studied extensively, and diverse supports such as clay, [31] carbon nanofibres, [32] montmorillonite, [33] magnetic mesoporous silica, [34] zeolite [35] and metal oxides [36] have been investigated. A current challenge in this area is the development of efficient immobilized systems that can simultaneously fulfil the usual targets of achieving high turnover number values and facilitate recovery and reuse as well as...