Ammonium molybdate

All chemicals were purchased in analytical grade and used as received. Polysulfone (PSf) beads (UDEL P-3500 LCD MB7, Solvay advanced polymers, L.L.C) and N-methyl-2-pyrrolidone (NMP, Macron, USA) were used to prepare the support layer. Polyvinyl pyrrolidone (PVP, Acros, Pittsburgh, PA, USA) and lithium chloride (LiCl, anhydrous > 99%) were employed as additives in the PSf casting solution. Sodium dodecyl sulfate (SDS, Showa, Japan), 1,3,5-benzenetricarbonyl trichloride (TMC, 98%, Tokyo Chemicals Industry Co., Ltd., Tokyo, Japan), and m-Phenylenediamine (MPD, >99%, Acros, New York, NY, USA) were used to prepare the PA-selective layer. Sodium chloride (NaCl) was purchased from Taiwan Biotech. HNO₃, disodium hydrogen phosphate, ammonium molybdate, ammonium ceric sulphate, benzoguanamine, and acetoguanamine were all purchased from Alfa Aesar (Ward Hill, MA, USA). The nanoparticles of graphene oxide (GO, diameter: 90 nm) and titanium dioxide (TiO₂, Degussa P-25, diameter: 20 nm) were purchased from UniRegion Bio-Tech (Taiwan) and Showa (Tokyo, Japan) for modifying the active layer of the FO membranes.

Iron(III) chloride hexahydrate (CAS: 10025-77-1), urea 99.3+% (CAS: 57-13-6), ethylene glycol 99% (CAS: 107-21-1), trisodium citrate dihydrate 99% (CAS: 6132-04-3), ammonium molybdate 99% (CAS 13106-76-8), zinc(II) chloride 98% (CAS 7646 85 7), and cobalt(II) chloride hexahydrate 98% (CAS 7791-13-1) were supplied by Alfa Aesar. Succinic acid (CAS: 110-15-6), ammonium hydroxide solution 25% (CAS: 1336-21-6), and nickel(II) chloride 98% (CAS 7718-54-9) were provided by Sigma-Aldrich, and cetyltrimethylammonium bromide 99% (CTAB) (CAS: 57-09-0) by Roth. Deionized water was used for all experiments.

Roundup (commercial grade, 41%, containing 360 g/L glyphosate) was diluted to prepare a 1000 mg/L glyphosate stock solution with a natural pH of 4.9–5.9. Calcium peroxide (CaO₂, 65%), ammonium molybdate (H₈MoN₂O₄, 99%), and ascorbic acid (C₆H₈O₆, 99%) was purchased from Alfa Aesar, Ward Hill, MA, USA. Calcium chloride (CaCl₂, ≥99.5%), hydrogen peroxide (H₂O₂, 30%), ammonia solution (NH₄OH, 25 wt%), ferrous sulfate (FeSO₄∙7H₂O, ≥98%), and ethyl alcohol (C₂H₅OH, 95%) were supplied from R&M Chemicals Sdn. Bhd. (Semenyih, Malaysia). Polyethylene glycol 200 [HO(C₂H₄O)nH, PEG 200], antimony potassium tartrate [K₂Sb₂(C₄H₂O₆)₂, 99%], sodium sulfite (Na₂SO₃, ≥98%, 2.0 M), sodium hydroxide (NaOH), and sulfuric acid (H₂SO₄, 95%) were procured from Sigma Aldrich (St Louis, MO, USA). Cerium (IV) sulfate tetrahydrate (CeO₈S₂∙4H₂O, ≥98%) was purchased from Acros Organics, Geel, Belgium. All the chemical reagents used in this study were of analytical reagent grade. Distilled water was used throughout the experiments to prepare the solutions and the stock solutions were freshly prepared every week. The pH of the solutions was adjusted by the addition of 0.1 M H₂SO₄ solution and 0.1 M NaOH solution.

Next, 100-μL portions of Fusarium sp. DS 682 spore suspension were added to M9 PDA plates, followed by incubation at 28°C for 2 weeks. M9 PDA medium was prepared by adding micronutrients (see recipe below), 24 g/L potato dextrose (BD Biosciences, San Jose, CA), and 2% granulated agar (BD Biosciences) to M9 salts (MP Biomedicals, Irvine, CA) in Millipore water. The micronutrients consisted of 0.145 mM ammonium molybdate (Thermo Fisher Scientific), 2 mM boric acid (Sigma-Aldrich, St. Louis, MO), 0.151 mM cobalt chloride (Sigma-Aldrich), 0.048 mM cupric sulfate (Sigma-Aldrich), 0.404 mM manganese chloride (Sigma-Aldrich), and 0.048 mM zinc sulfate (Thermo Fisher Scientific). These micronutrients were added after autoclaving the M9 PDA solution, when the solution was ~55°C. After pouring the M9 PDA into petri dishes, the solidified agar plates were wrapped in Parafilm and stored at 4°C for future use. M9 PDA plates were primarily used to maintain the fungal cultures and not in the micromodel experiments described in this paper. The fungal experiments in the micromodel and for proteomics analysis were conducted using PDA plugs and PDA plates, respectively, as described in detail below.

Nutrient broth, nutrient agar (HiMedia, Mumbai, India); K₂HPO₄, CaCl₂, NaOH, ammonium persulfate, nanohydroxyapatite (Sigma-Aldrich, Missouri, USA); gluconic acid, sulphuric acid, nitric acid, hydrochloric acid (Merck Millipore, Massachusetts, USA); ammonium molybdate, antimony potassium, ascorbic acid (Fischer Scientific, Massachusetts, USA), nanohydroxyapatite Sisco Research Laboratories Pvt. Ltd. (Mumbai, Maharashtra, India).